|Detection of Human, Mouse, and Rat SH2B1 by Western Blot. Western blot shows lysates of LNCaP human prostate cancer cell line, Neuro‑2A mouse neuroblastoma cell line, and Rat‑2 rat embryonic fibroblast cell line. PVDF membrane was probed with 1 µg/mL of Goat Anti-Human/Mouse/Rat SH2B1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF6915) followed by HRP-conjugated Anti-Goat IgG Secondary Antibody (Catalog # HAF017). A specific band was detected for SH2B1 at approximately 90 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.|
SH2B1 (Src-Homology 2 Domain-Containing protein B1/1B; also SH2B1 alpha, PSM and SH2B adaptor protein 1) is a member of the SH2B adapter family of proteins. Although its predicted MW is 80 kDa, it runs anomalously at 90-102 kDa in SDS-Page. SH2B1 is a nucleocytoplasmic protein that is widely expressed in cells such as skeletal muscle cells, neurons, and adipocytes. It serves as a linker between Jak2 and multiple downstream molecules such as Rac and IRS1. It does this following phosphorylation on a number of potential sites. It also promotes the enzymatic activity of associated receptor kinases, thus potentiating ligand-receptor interactions. SH2B1 appears to bind to nonphosphorylated Jaks as a monomer, while Jak phosphorylation induces SH2B1 dimerization. SH2B1 is further reported to form a homopentamer, and to oligomerize with SH2B2. Human SH2B1( alpha ) is 756 amino acids amino acids (aa) in length. It contains one dimerization segment (aa 24-85), an NLS (aa 224-233), one pleckstrin homology region (aa 249-378) and an SH2 domain (aa 521-625). At least three utilized phosphorylation sites exist. There are at least two splice variants for SH2B1. The 90-92 kDa SH2B1 beta isoform shows a 39 aa substitution for aa 633-756, while the SH2B1 gamma isoform possesses a 50 aa substitution for the same aa range (i.e., aa 633-756). Over aa 317-467, human SH2B1 shares 92% aa identity with mouse SH2B1.