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Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Heat-Shock Proteins: Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.Cold Shock Proteins and Peptides: Cellular proteins and peptides that are induced in response to cold stress. They are found in a broad variety of prokaryotic and eukaryotic organisms.Heat-Shock Response: A constellation of responses that occur when an organism is exposed to excessive heat. Responses include synthesis of new proteins and regulation of others.Bacterial Proteins: Proteins found in any species of bacterium.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.HSP70 Heat-Shock Proteins: A class of MOLECULAR CHAPERONES found in both prokaryotes and in several compartments of eukaryotic cells. These proteins can interact with polypeptides during a variety of assembly processes in such a way as to prevent the formation of nonfunctional structures.Cold-Shock Response: A constellation of responses that occur when an organism is exposed to excessive cold. In humans, a fall in skin temperature triggers gasping, hypertension, and hyperventilation.Shock, Septic: Sepsis associated with HYPOTENSION or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to LACTIC ACIDOSIS; OLIGURIA; or acute alteration in mental status.Shock: A pathological condition manifested by failure to perfuse or oxygenate vital organs.HSP72 Heat-Shock Proteins: Stress-inducible members of the heat-shock proteins 70 family. HSP72 heat shock proteins function with other MOLECULAR CHAPERONES to mediate PROTEIN FOLDING and to stabilize pre-existent proteins against aggregation.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.HSP90 Heat-Shock Proteins: A class of MOLECULAR CHAPERONES whose members act in the mechanism of SIGNAL TRANSDUCTION by STEROID RECEPTORS.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Shock, Hemorrhagic: Acute hemorrhage or excessive fluid loss resulting in HYPOVOLEMIA.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Common Cold: A catarrhal disorder of the upper respiratory tract, which may be viral or a mixed infection. It generally involves a runny nose, nasal congestion, and sneezing.Acclimatization: Adaptation to a new environment or to a change in the old.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Molecular Chaperones: A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.Sigma Factor: A protein which is a subunit of RNA polymerase. It effects initiation of specific RNA chains from DNA.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Panstrongylus: A genus of cone-nosed bugs of the subfamily TRIATOMINAE. Its species are vectors of TRYPANOSOMA CRUZI.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Chaperonin 60: A group I chaperonin protein that forms the barrel-like structure of the chaperonin complex. It is an oligomeric protein with a distinctive structure of fourteen subunits, arranged in two rings of seven subunits each. The protein was originally studied in BACTERIA where it is commonly referred to as GroEL protein.Genes, Bacterial: The functional hereditary units of BACTERIA.Lactams, Macrocyclic: LACTAMS forming compounds with a ring size of approximately 1-3 dozen atoms.Electrophoresis, Gel, Two-Dimensional: Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.HSP40 Heat-Shock Proteins: A family of heat-shock proteins that contain a 70 amino-acid consensus sequence known as the J domain. The J domain of HSP40 heat shock proteins interacts with HSP70 HEAT-SHOCK PROTEINS. HSP40 heat-shock proteins play a role in regulating the ADENOSINE TRIPHOSPHATASES activity of HSP70 heat-shock proteins.Benzoquinones: Benzene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.HSP30 Heat-Shock Proteins: A subfamily of small heat-shock proteins found in a wide variety of organisms.Proteostasis Deficiencies: Disorders caused by imbalances in the protein homeostasis network - synthesis, folding, and transport of proteins; post-translational modifications; and degradation or clearance of misfolded proteins.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Chaperonins: A family of multisubunit protein complexes that form into large cylindrical structures which bind to and encapsulate non-native proteins. Chaperonins utilize the energy of ATP hydrolysis to enhance the efficiency of PROTEIN FOLDING reactions and thereby help proteins reach their functional conformation. The family of chaperonins is split into GROUP I CHAPERONINS, and GROUP II CHAPERONINS, with each group having its own repertoire of protein subunits and subcellular preferences.HSP27 Heat-Shock Proteins: A subfamily of small heat-shock proteins that function as molecular chaperones that aid in refolding of non-native proteins. They play a protective role that increases cellular survival during times of stress.Shock, Cardiogenic: Shock resulting from diminution of cardiac output in heart disease.Freezing: Liquids transforming into solids by the removal of heat.Bacillus subtilis: A species of gram-positive bacteria that is a common soil and water saprophyte.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Chaperonin 10: A group I chaperonin protein that forms a lid-like structure which encloses the non-polar cavity of the chaperonin complex. The protein was originally studied in BACTERIA where it is commonly referred to as GroES protein.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Thermosensing: The sensation of cold, heat, coolness, and warmth as detected by THERMORECEPTORS.Y-Box-Binding Protein 1: Y-box-binding protein 1 was originally identified as a DNA-binding protein that interacts with Y-box PROMOTER REGIONS of MHC CLASS II GENES. It is a highly conserved transcription factor that regulates expression of a wide variety of GENES.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Celastraceae: A plant family of the order Celastrales, subclass Rosidae, class Magnoliopsida.Archaeoglobales: An order of extremely thermophilic, sulfate-reducing archaea, in the kingdom EURYARCHAEOTA. The single family Archaeoglobaceae contains one genus ARCHAEOGLOBUS.Aconitic AcidCloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Prokaryotic Initiation Factor-1: The smallest of the three prokaryotic initiation factors with a molecular size of approximately 8 kD. It binds near the A-site of the 30S subunit of RIBOSOMES and may play a role in preventing premature addition of aminoacyl-tRNA-linked PEPTIDE ELONGATION FACTOR TU to the ribosome during the initiation of a peptide chain (PEPTIDE CHAIN INITIATION, TRANSLATIONAL).Arsenites: Inorganic salts or organic esters of arsenious acid.Cold Climate: A climate characterized by COLD TEMPERATURE for a majority of the time during the year.Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Vibrio cholerae O139: Strains of VIBRIO CHOLERAE containing O ANTIGENS group 139. This strain emerged in India in 1992 and caused a CHOLERA epidemic.Shock, Traumatic: Shock produced as a result of trauma.Malpighian Tubules: Slender tubular or hairlike excretory structures found in insects. They emerge from the alimentary canal between the mesenteron (midgut) and the proctodeum (hindgut).Arctium: A plant genus of the family ASTERACEAE. Arctiin (LIGNANS) is in the seed.Kinetics: The rate dynamics in chemical or physical systems.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Cold Ischemia: The chilling of a tissue or organ during decreased BLOOD perfusion or in the absence of blood supply. Cold ischemia time during ORGAN TRANSPLANTATION begins when the organ is cooled with a cold perfusion solution after ORGAN PROCUREMENT surgery, and ends after the tissue reaches physiological temperature during implantation procedures.RNA-Binding Proteins: Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.Sodium Compounds: Inorganic compounds that contain sodium as an integral part of the molecule.Polyribonucleotide Nucleotidyltransferase: An enzyme of the transferase class that catalyzes the reaction RNA(n+1) and orthophosphate to yield RNA(n) and a nucleoside diphosphate, or the reverse reaction. ADP, IDP, GDP, UDP, and CDP can act as donors in the latter case. (From Dorland, 27th ed) EC 2.7.7.8.Sodium Salicylate: A non-steroidal anti-inflammatory agent that is less effective than equal doses of ASPIRIN in relieving pain and reducing fever. However, individuals who are hypersensitive to ASPIRIN may tolerate sodium salicylate. In general, this salicylate produces the same adverse reactions as ASPIRIN, but there is less occult gastrointestinal bleeding. (From AMA Drug Evaluations Annual, 1992, p120)beta-Galactosidase: A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.ATP-Dependent Proteases: Proteases that contain proteolytic core domains and ATPase-containing regulatory domains. They are usually comprised of large multi-subunit assemblies. The domains can occur within a single peptide chain or on distinct subunits.Chloramphenicol: An antibiotic first isolated from cultures of Streptomyces venequelae in 1947 but now produced synthetically. It has a relatively simple structure and was the first broad-spectrum antibiotic to be discovered. It acts by interfering with bacterial protein synthesis and is mainly bacteriostatic. (From Martindale, The Extra Pharmacopoeia, 29th ed, p106)Blotting, Northern: Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Gene Expression Regulation, Archaeal: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in archaea.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Artificial Gene Fusion: The in vitro fusion of GENES by RECOMBINANT DNA techniques to analyze protein behavior or GENE EXPRESSION REGULATION, or to merge protein functions for specific medical or industrial uses.Withanolides: Ergostane derivatives of 28 carbons with oxygens at C1, C22, and C26 positions and the side chain cyclized. They are found in WITHANIA plant genus and have cytotoxic and other effects.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Heat Stress Disorders: A group of conditions that develop due to overexposure or overexertion in excessive environmental heat.RNA Helicases: A family of proteins that promote unwinding of RNA during splicing and translation.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Mutagenesis, Insertional: Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.Operon: In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)High-Energy Shock Waves: High-amplitude compression waves, across which density, pressure, and particle velocity change drastically. The mechanical force from these shock waves can be used for mechanically disrupting tissues and deposits.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Laryngeal Mucosa: The mucous lining of the LARYNX, consisting of various types of epithelial cells ranging from stratified squamous EPITHELIUM in the upper larynx to ciliated columnar epithelium in the rest of the larynx, mucous GOBLET CELLS, and glands containing both mucous and serous cells.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Benzyl Alcohol: A colorless liquid with a sharp burning taste and slight odor. It is used as a local anesthetic and to reduce pain associated with LIDOCAINE injection. Also, it is used in the manufacture of other benzyl compounds, as a pharmaceutic aid, and in perfumery and flavoring.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Semen Preservation: The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Osmotic Pressure: The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.HeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Exoribonucleases: A family of enzymes that catalyze the exonucleolytic cleavage of RNA. It includes EC 3.1.13.-, EC 3.1.14.-, EC 3.1.15.-, and EC 3.1.16.-. EC 3.1.-Thermotoga maritima: A rod-shaped bacterium surrounded by a sheath-like structure which protrudes balloon-like beyond the ends of the cell. It is thermophilic, with growth occurring at temperatures as high as 90 degrees C. It is isolated from geothermally heated marine sediments or hot springs. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Regulon: In eukaryotes, a genetic unit consisting of a noncontiguous group of genes under the control of a single regulator gene. In bacteria, regulons are global regulatory systems involved in the interplay of pleiotropic regulatory domains and consist of several OPERONS.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Protein Denaturation: Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Gene Expression Regulation, Fungal: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.Agrobacterium tumefaciens: A species of gram-negative, aerobic bacteria isolated from soil and the stems, leafs, and roots of plants. Some biotypes are pathogenic and cause the formation of PLANT TUMORS in a wide variety of higher plants. The species is a major research tool in biotechnology.Moraxella (Branhamella) catarrhalis: Gram-negative aerobic cocci of low virulence that colonize the nasopharynx and occasionally cause MENINGITIS; BACTEREMIA; EMPYEMA; PERICARDITIS; and PNEUMONIA.Sperm Motility: Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.Fever: An abnormal elevation of body temperature, usually as a result of a pathologic process.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Quinones: Hydrocarbon rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.NFI Transcription Factors: Transcription factors that were originally identified as site-specific DNA-binding proteins essential for DNA REPLICATION by ADENOVIRUSES. They play important roles in MAMMARY GLAND function and development.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Sequence Homology: The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.Aequorin: A photoprotein isolated from the bioluminescent jellyfish Aequorea. It emits visible light by an intramolecular reaction when a trace amount of calcium ion is added. The light-emitting moiety in the bioluminescence reaction is believed to be 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (AF-350).