Adaptor Protein Complex mu Subunits: A family of medium adaptin protein subunits of approximately 45 KDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 3 and ADAPTOR PROTEIN COMPLEX 4.Adaptor Protein Complex 3: An adaptor protein complex found primarily on perinuclear compartments.Adaptor Protein Complex 1: A clathrin adaptor protein complex primarily involved in clathrin-related transport at the TRANS-GOLGI NETWORK.Adaptor Protein Complex 2: An adaptor protein complex primarily involved in the formation of clathrin-related endocytotic vesicles (ENDOSOMES) at the CELL MEMBRANE.Adaptor Protein Complex 4: An adaptor protein complex involved in transport of molecules between the TRANS-GOLGI NETWORK and the endosomal-lysosomal system.Adaptor Protein Complex Subunits: The subunits that make up the large, medium and small chains of adaptor proteins.Adaptor Protein Complex delta Subunits: A family of large adaptin protein subunits of approximately 130-kDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 3.Adaptor Proteins, Vesicular Transport: A class of proteins involved in the transport of molecules via TRANSPORT VESICLES. They perform functions such as binding to the cell membrane, capturing cargo molecules and promoting the assembly of CLATHRIN. The majority of adaptor proteins exist as multi-subunit complexes, however monomeric varieties have also been found.Adaptor Protein Complex gamma Subunits: A family of large adaptin protein subunits of approximately 90 KDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 1.Adaptor Protein Complex beta Subunits: A family of large adaptin protein complex subunits of approximately 90-130 kDa in size.Adaptor Protein Complex alpha Subunits: A family of large adaptin protein subunits of approximately 100 kDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 2.Adaptor Proteins, Signal Transducing: A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymesClathrin: The main structural coat protein of COATED VESICLES which play a key role in the intracellular transport between membranous organelles. Each molecule of clathrin consists of three light chains (CLATHRIN LIGHT CHAINS) and three heavy chains (CLATHRIN HEAVY CHAINS) that form a structure called a triskelion. Clathrin also interacts with cytoskeletal proteins.Human Characteristics: The fundamental dispositions and traits of humans. (Merriam-Webster's Collegiate Dictionary, 10th ed)Monomeric Clathrin Assembly Proteins: A subclass of clathrin assembly proteins that occur as monomers.GRB2 Adaptor Protein: A signal transducing adaptor protein that links extracellular signals to the MAP KINASE SIGNALING SYSTEM. Grb2 associates with activated EPIDERMAL GROWTH FACTOR RECEPTOR and PLATELET-DERIVED GROWTH FACTOR RECEPTORS via its SH2 DOMAIN. It also binds to and translocates the SON OF SEVENLESS PROTEINS through its SH3 DOMAINS to activate PROTO-ONCOGENE PROTEIN P21(RAS).Shc Signaling Adaptor Proteins: A family of signaling adaptor proteins that contain SRC HOMOLOGY DOMAINS. Many members of this family are involved in transmitting signals from CELL SURFACE RECEPTORS to MITOGEN-ACTIVATED PROTEIN KINASES.Adaptor Protein Complex sigma Subunits: A family of small adaptin protein complex subunits of approximately 19 KDa in size.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.Protein Subunits: Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.Endocytosis: Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.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.Coated Vesicles: Vesicles formed when cell-membrane coated pits (COATED PITS, CELL-MEMBRANE) invaginate and pinch off. The outer surface of these vesicles are covered with a lattice-like network of coat proteins, such as CLATHRIN, coat protein complex proteins, or CAVEOLINS.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.