PAG1
PAG1 (phosphoprotein membrane anchor with glycosphingolipid microdomains 1, also known as PAG or CBP) is a type III transmembrane adaptor protein at the cell membrane. It negatively regulates immune receptor signalling by recruiting the tyrosine kinase CSK to lipid rafts. Browse Assay Genie's current range of PAG1 research reagents below, or read on for the biology behind the target.
PAG1 acts as a brake on immune cell activation. It negatively regulates T-cell antigen receptor (TCR)-mediated signalling in T-cells and FCER1 (high affinity immunoglobulin epsilon receptor)-mediated signalling in mast cells. Its mechanism centres on the tyrosine kinase CSK: PAG1 promotes CSK activation and recruitment to lipid rafts, which in turn results in inhibition of LCK. PAG1 also inhibits immunological synapse formation by preventing the dynamic arrangement of lipid raft proteins, and it may be involved in cell adhesion signalling.
The PAG1 gene encodes a type III transmembrane adaptor protein that binds CSK, and the protein is located at the cell membrane. As an adaptor it has no catalytic activity of its own; it organises signalling components within membrane microdomains. This makes it a useful reference point for studies of how raft-associated kinases are held in check in resting lymphocytes and mast cells. Researchers working with PAG1 protein, PAG1 antibody or PAG1 ELISA kit reagents typically do so in the context of T-cell activation and receptor signalling.
The protein was originally named for its association with glycosphingolipid-enriched microdomains, and the approved HGNC name, phosphoprotein membrane anchor with glycosphingolipid microdomains 1, reflects this history. Older symbols include PAG and CBP, the latter referring to its role as a CSK-binding protein. Orthologues of the gene are designated Pag1 in both mouse and rat.
PAG1 negatively regulates TCR-mediated signalling and is thought to be involved in controlling T-cell activation.
PAG1 regulates FCER1-mediated signalling in mast cells, making it relevant to studies of high affinity IgE receptor responses.
PAG1 recruits CSK to lipid rafts and limits the dynamic arrangement of raft proteins during immunological synapse formation.
PAG1 promotes CSK activation and recruitment, leading to LCK inhibition, so it is a focus for studies of Src-family kinase control.
PAG1 is a negative regulator of immune receptor signalling. It promotes CSK activation and recruitment to lipid rafts, which results in LCK inhibition, dampening TCR signalling in T-cells and FCER1 signalling in mast cells. It also inhibits immunological synapse formation and may contribute to cell adhesion signalling.
PAG and CBP are earlier symbols for the same gene. CBP refers to its function as a CSK-binding protein, while PAG derives from the previous name, phosphoprotein associated with glycosphingolipid microdomains 1. The current HGNC name is phosphoprotein membrane anchor with glycosphingolipid microdomains 1.
Yes. Orthologues designated Pag1 are annotated in both mouse and rat, so rodent models can be used to study its role in lymphocyte and mast cell signalling. Cross-species use of any reagent depends on the product, so check the datasheet of any product for its validated reactivity.
Other T-cell signalling adaptors, Src-family kinases and immune receptor components with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q9NWQ8; product specifications from Assay Genie datasheets.