Protein Domain : STAT5b, SH2 domain IPR035886

Type	Domain
Description	This entry represents the SH2 domain of STAT5b.STAT5 is a member of the STAT family of transcription factors. Two highly related proteins, STAT5a and STAT5b are encoded by separate genes, but are 90% identical at the amino acid level. Both STAT5a and STAT5b are ubiquitously expressed and functionally interchangeable. They regulate B and T cell development [ , ]. These proteins are central signalling molecules in leukaemias driven by Abelson fusion tyrosine kinases, having a key role in resistance of leukaemic cells against treatment with tyrosine kinase inhibitors (TKI) []. They differentially regulate cellular behaviour in human mammary carcinoma []. STAT proteins have a dual function: signal transduction and activation of transcription. When cytokines are bound to cell surface receptors, the associated Janus kinases (JAKs) are activated, leading to tyrosine phosphorylation of the given STAT proteins [ ]. Phosphorylated STATs form dimers, translocate to the nucleus, and bind specific response elements to activate transcription of target genes []. STAT proteins contain an N-terminal domain (NTD), a coiled-coil domain (CCD), a DNA-binding domain (DBD), an α-helical linker domain (LD), an SH2 domain, and a transactivation domain (TAD). The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6 [].
Short Name	STAT5b_SH2