Tensin/EPS8 phosphotyrosine-binding domain (IPR013625)

Short name: PTB

Overlapping homologous superfamilies

Domain relationships


The phosphotyrosine-binding domain (PTB, also phosphotyrosine-interaction or PI domain) of tensin tends to be found at the C terminus. Tensin is a multi-domain protein that binds to actin filaments and functions as a focal-adhesion molecule (focal adhesions are regions of plasma membrane through which cells attach to the extracellular matrix). Human tensin has actin-binding sites, an SH2 (IPR000980) domain and a region similar to the tumour suppressor PTEN [PMID: 11023826]. The PTB domain interacts with the cytoplasmic tails of beta integrin by binding to an NPXY motif [PMID: 14592531]. The PTB domain is also found in the epidermal growth factor receptor kinase substrate 8 (EPS8).

PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules [PMID: 10610414]. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether [PMID: 11911882]. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine [PMID: 11994738]. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains [PMID: 15567406].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005515 protein binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.