Adaptor protein
Encyclopedia
Signal transducing adaptor proteins are protein
s which are accessory to main proteins in a signal transduction
pathway. These proteins tend to lack any intrinsic enzymatic activity themselves but instead mediate specific protein–protein interactions that drive the formation of protein complexes. Examples of adaptor proteins include MyD88
, Grb2
and SHC1
.
depends on the recruitment of several signalling components such as protein kinases and G-protein GTPase
s into short lived active complexes in response to an activating signal such as a growth factor
binding to its receptor
.
and SH3 domain
s) which 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 which allow a rich diversity of specific and coordinated protein–protein interactions to occur within the cell during signal transduction
.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s which are accessory to main proteins in a signal transduction
Signal transduction
Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...
pathway. These proteins tend to lack any intrinsic enzymatic activity themselves but instead mediate specific protein–protein interactions that drive the formation of protein complexes. Examples of adaptor proteins include MyD88
Myd88
Myeloid differentiation primary response gene is a protein that, in humans, is encoded by the MYD88 gene.-Function:In mice, MyD88 is a universal adapter protein as it is used by all TLRs to activate the transcription factor NF-κB. Mal is necessary to recruit Myd88 to TLR 2 and TLR 4, and MyD88...
, Grb2
Grb2
Growth factor receptor-bound protein 2 also known as Grb2 is an adaptor protein involved in signal transduction/cell communication. In humans, the GRB2 protein is encoded by the GRB2 gene....
and SHC1
SHC1
SHC-transforming protein 1 is a protein that in humans is encoded by the SHC1 gene. SHC has been found to be important in the regulation of apoptosis and drug resistance in mammalian cells....
.
Signalling components
Much of the specificity of signal transductionSignal transduction
Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...
depends on the recruitment of several signalling components such as protein kinases and G-protein GTPase
GTPase
GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate . The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases.-Functions:...
s into short lived active complexes in response to an activating signal such as a growth factor
Growth factor
A growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes....
binding to its receptor
Receptor (biochemistry)
In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...
.
Domains
Adaptor proteins usually contain several domains within their structure (e.g., Src homology 2 (SH2)SH2 domain
The SH2 domain is a structurally conserved protein domain contained within the Src oncoprotein and in many other intracellular signal-transducing proteins...
and SH3 domain
SH3 domain
The SRC Homology 3 Domain is a small protein domain of about 60 amino acids residues first identified as a conserved sequence in the viral adaptor protein v-Crk and the non-catalytic parts of enzymes such as phospholipase and several cytoplasmic tyrosine kinases such as Abl and Src...
s) which 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
Proline
Proline is an α-amino acid, one of the twenty DNA-encoded amino acids. Its codons are CCU, CCC, CCA, and CCG. It is not an essential amino acid, which means that the human body can synthesize it. It is unique among the 20 protein-forming amino acids in that the α-amino group is secondary...
-rich sequences within specific peptide sequence contexts of proteins.
There are many other types of interaction domains found within adaptor and other signalling proteins which allow a rich diversity of specific and coordinated protein–protein interactions to occur within the cell during signal transduction
Signal transduction
Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...
.
Genes
Genes encoding adaptor proteins include:- BCAR3BCAR3Breast cancer anti-estrogen resistance protein 3 is a protein that in humans is encoded by the BCAR3 gene.-Further reading:...
– Breast cancer anti-estrogen resistance protein 3 - GRAPGRAPGRB2-related adapter protein is a protein that in humans is encoded by the GRAP gene.This gene encodes a member of the GRB2/Sem5 /Drk family. This member functions as a cytoplasmic signaling protein which contains an SH2 domain flanked by two SH3 domains...
– GRB2-related adaptor protein - GRAP2GRAP2GRB2-related adapter protein 2 is a protein that in humans is encoded by the GRAP2 gene.-Interactions:GRAP2 has been shown to interact with CD28, STAMBP, CCNDBP1, Linker of activated T cells, Lymphocyte cytosolic protein 2 and MAP4K1....
– GRB2-related adaptor protein 2 - LDLRAP1LDLRAP1Low density lipoprotein receptor adapter protein 1 is a protein that in humans is encoded by the LDLRAP1 gene.-Interactions:LDLRAP1 has been shown to interact with AP2B1 and LRP2.-Further reading:...
– low density lipoprotein receptor adaptor protein 1 - NCK1NCK1Cytoplasmic protein NCK1 is a protein that in humans is encoded by the NCK1 gene.-Interactions:NCK1 has been shown to interact with DNM1, EIF2B2, KHDRBS1, Lymphocyte cytosolic protein 2, EPH receptor B1, SOCS7, MINK1, MAP4K1, MAP4K4, Abl gene, WIPF1, RRAS, Wiskott-Aldrich syndrome protein,...
– NCK adaptor protein 1 - NCK2NCK2Cytoplasmic protein NCK2 is a protein that in humans is encoded by the NCK2 gene.-Interactions:NCK2 has been shown to interact with LIMS1, Epidermal growth factor receptor, PDGFRB, PTK2, T-cell surface glycoprotein CD3 epsilon chain and TrkB....
– NCK adaptor protein 2 - NOS1APNOS1APNitric oxide synthase 1 adaptor protein also known as carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase protein is a protein that in humans is encoded by the NOS1AP gene....
– nitric oxide synthase 1 (neuronal) adaptor protein - PIK3AP1PIK3AP1Phosphoinositide 3-kinase adapter protein 1 is an enzyme that in humans is encoded by the PIK3AP1 gene.-Further reading:...
– phosphoinositide-3-kinase adaptor protein 1 - SH2B1SH2B1SH2B adapter protein 1 is a protein that in humans is encoded by the SH2B1 gene.-Interactions:SH2B1 has been shown to interact with Insulin receptor, Grb2, TrkA and Janus kinase 2.- Clinical significance :...
– SH2B adaptor protein 1 - SH2B2SH2B2SH2B adapter protein 2 is a protein that in humans is encoded by the SH2B2 gene.-Interactions:SH2B2 has been shown to interact with TrkA and Cbl gene.-Further reading:...
– SH2B adaptor protein 2 - SH2B3SH2B3SH2B adapter protein 3 is a protein that in humans is encoded by the SH2B3 gene.-Further reading:...
– SH2B adaptor protein 3 - SH2D3ASH2D3ASH2 domain-containing protein 3A is a protein that in humans is encoded by the SH2D3A gene.-Interactions:SH2D3A has been shown to interact with Epidermal growth factor receptor.-Further reading:...
-SH2 domain containing 3A - SH2D3CSH2D3CSH2 domain containing 3C, also known as SH2D3C, is a protein that in humans is encoded by the SH2D3C gene.- Function :Sh2d3c is a gene on human chromosome 9 that encodes an SH2 domain containing protein known as NSP3. The mouse homologue is found on chromosome 2...
– SH2 domain containing 3C - SHBSHB (gene)SH2 domain-containing adapter protein B is a protein that in humans is encoded by the SHB gene.-Interactions:SHB has been shown to interact with Fibroblast growth factor receptor 1, Src, Linker of activated T cells, Lymphocyte cytosolic protein 2, ZAP-70, EPS8, PIK3R1 and VAV1.-Further reading:...
– Src homology 2 domain containing adaptor protein B - SLC4A1AP – solute carrier family 4 (anion exchanger), member 1, adaptor protein
- GAB2GAB2GRB2-associated-binding protein 2 is a protein that in humans is encoded by the GAB2 gene.The protein encoded by this gene, GAB2 is an adaptor protein serving as principal activator of Phosphatidylinositol 3-kinase...
– GRB2-associated binding protein 2
See also
- Wikipedia:MeSH D12.776#MeSH D12.776.157.057 --- adaptor proteins.2C signal transducing
- Wikipedia:MeSH D12.776#MeSH D12.776.543.990.150 --- adaptor proteins.2C vesicular transport