Signal transducing adaptor proteins (STAPs) are

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s that are accessory to main proteins in a

signal transduction Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular ...

pathway. Adaptor proteins contain a variety of protein-binding modules that link protein-binding partners together and facilitate the creation of larger signaling complexes. These proteins tend to lack any intrinsic enzymatic activity themselves, instead mediating specific protein–protein interactions that drive the formation of protein complexes. Examples of adaptor proteins include MYD88, Grb2 and SHC1.

Signaling components

Much of the specificity of

depends on the recruitment of several signalling components such as

protein kinases A protein kinase is a kinase which selectively modifies other proteins by covalently adding phosphates to them (phosphorylation) as opposed to kinases which modify lipids, carbohydrates, or other molecules. Phosphorylation usually results in a fun ...

and G-protein

GTPase GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a ...

s into short-lived active complexes in response to an activating signal such as a

growth factor A growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Usually it is a secreted protein or a steroid hormone. Growth factors are important for r ...

binding to its receptor.

Domains

Adaptor proteins usually contain several domains within their structure (e.g., Src homology 2 (SH2) and SH3 domains) that allow specific interactions with several other specific proteins. SH2 domains recognise specific amino acid sequences within proteins containing phosphotyrosine residues and SH3 domains recognise proline-rich sequences within specific peptide sequence contexts of proteins. There are many other types of interaction domains found within adaptor and other signalling proteins that allow a rich diversity of specific and coordinated protein–protein interactions to occur within the cell during

Genes

Genes encoding adaptor proteins include: * BCAR3 – Breast cancer anti-estrogen resistance protein 3 * CBL – Casitas B-lineage Lymphoma * FRS2 – Fibroblast growth factor receptor substrate 2 * GAB2 – GRB2-associated binding protein 2 * GRAP – GRB2-related adaptor protein * GRAP2 – GRB2-related adaptor protein 2 * GRB2 – Growth factor receptor-bound protein 2 * IRS1 – Insulin receptor substrate 1 * LDLRAP1 – low-density lipoprotein receptor adaptor protein 1 * MYD88 - Myeloid differentiation primary response gene 88 * NCDN - Neurochondrin *

NCK1 Cytoplasmic protein NCK1 is a protein that in humans is encoded by the ''NCK1'' gene. Gene The Nck (non-catalytic region of tyrosine kinase adaptor protein 1) belongs to the adaptor family of proteins. The nck gene was initially isolated from ...

– NCK adaptor protein 1 * NCK2 – NCK adaptor protein 2 * NOS1AP – nitric oxide synthase 1 (neuronal) adaptor protein * PIK3AP1 – phosphoinositide-3-kinase adaptor protein 1 * SH2B1 – SH2B adaptor protein 1 * SH2B2 – SH2B adaptor protein 2 * SH2B3 – SH2B adaptor protein 3 * SH2D3A -SH2 domain containing 3A * SH2D3C – SH2 domain containing 3C * SNTA1 – Syntrophin, alpha 1 * SHB – Src homology 2 domain containing adaptor protein B * SLC4A1AP – solute carrier family 4 (anion exchanger), member 1, adaptor protein

Signaling components

Domains

Genes

See also

References

Further reading