Caseins: A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.Casein Kinases: A group of protein-serine-threonine kinases that was originally identified as being responsible for the PHOSPHORYLATION of CASEINS. They are ubiquitous enzymes that have a preference for acidic proteins. Casein kinases play a role in SIGNAL TRANSDUCTION by phosphorylating a variety of regulatory cytoplasmic and regulatory nuclear proteins.Casein Kinase II: A ubiquitous casein kinase that is comprised of two distinct catalytic subunits and dimeric regulatory subunit. Casein kinase II has been shown to phosphorylate a large number of substrates, many of which are proteins involved in the regulation of gene expression.Casein Kinase I: A casein kinase that was originally described as a monomeric enzyme with a molecular weight of 30-40 kDa. Several ISOENZYMES of casein kinase I have been found which are encoded by separate genes. Many of the casein kinase I isoenzymes have been shown to play distinctive roles in intracellular SIGNAL TRANSDUCTION.Casein Kinase Iepsilon: A casein kinase I isoenzyme with specificity for proteins involved the regulation of the CIRCADIAN RHYTHM.Casein Kinase Idelta: A casein kinase I isoenzyme that plays a regulatory role in a variety of cellular functions including vesicular transport, CHROMOSOME SEGREGATION; CYTOKINESIS, developmental processes, and the CIRCADIAN RHYTHM.Casein Kinase Ialpha: A casein kinase I isoenzyme that plays a role in intracellular signaling pathways including the WNT SIGNALING PATHWAY, the CELL CYCLE, membrane trafficking, and RNA processing. Multiple isoforms of casein kinase I alpha exist and are due to ALTERNATIVE SPLICING.Dietary Proteins: Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.Soybean Proteins: Proteins which are present in or isolated from SOYBEANS.Vegetable Proteins: Proteins which are present in or isolated from vegetables or vegetable products used as food. The concept is distinguished from PLANT PROTEINS which refers to non-dietary proteins from plants.Protein Kinases: A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.Protein HydrolysatesPhosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Milk Proteins: The major protein constituents of milk are CASEINS and whey proteins such as LACTALBUMIN and LACTOGLOBULINS. IMMUNOGLOBULINS occur in high concentrations in COLOSTRUM and in relatively lower concentrations in milk. (Singleton and Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed, p554)Abomasum: The fourth stomach of ruminating animals. It is also called the "true" stomach. It is an elongated pear-shaped sac lying on the floor of the abdomen, on the right-hand side, and roughly between the seventh and twelfth ribs. It leads to the beginning of the small intestine. (From Black's Veterinary Dictionary, 17th ed)Mammary Glands, Animal: MAMMARY GLANDS in the non-human MAMMALS.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.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.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.Soybeans: An annual legume. The SEEDS of this plant are edible and used to produce a variety of SOY FOODS.Milk: The white liquid secreted by the mammary glands. It contains proteins, sugar, lipids, vitamins, and minerals.Lactalbumin: A major protein fraction of milk obtained from the WHEY.Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Serine: A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.Protein Deficiency: A nutritional condition produced by a deficiency of proteins in the diet, characterized by adaptive enzyme changes in the liver, increase in amino acid synthetases, and diminution of urea formation, thus conserving nitrogen and reducing its loss in the urine. Growth, immune response, repair, and production of enzymes and hormones are all impaired in severe protein deficiency. Protein deficiency may also arise in the face of adequate protein intake if the protein is of poor quality (i.e., the content of one or more amino acids is inadequate and thus becomes the limiting factor in protein utilization). (From Merck Manual, 16th ed; Harrison's Principles of Internal Medicine, 12th ed, p406)PhosphopeptidesPhosvitin: An egg yolk phosphoglycoprotein which contains about 90% of the yolk protein phosphorus. It is synthesized in the liver of the hen and transferred to the developing oocyte, where it is bound to lipoproteins within the yolk granules.Lactation: The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.Kinetics: The rate dynamics in chemical or physical systems.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Dichlororibofuranosylbenzimidazole: An RNA polymerase II transcriptional inhibitor. This compound terminates transcription prematurely by selective inhibition of RNA synthesis. It is used in research to study underlying mechanisms of cellular regulation.Peptide Mapping: Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Digestion: The process of breakdown of food for metabolism and use by the body.Milk Hypersensitivity: Allergic reaction to milk (usually cow's milk) or milk products. MILK HYPERSENSITIVITY should be differentiated from LACTOSE INTOLERANCE, an intolerance to milk as a result of congenital deficiency of lactase.Diet: Regular course of eating and drinking adopted by a person or animal.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Molecular Weight: The sum of the weight of all the atoms in a molecule.Phosphoproteins