HPK1 (human, recombinant)

Hematopoietic progenitor kinase 1 (HPK1) is a Ste20-like protein serine/threonine kinase and member of the MAP4K family with roles in cell signaling and immune regulation. It is composed of an N-terminal kinase domain, a central region that contains four proline-rich sequences, a caspase cleavage site, and a C-terminal citron homology domain. HPK1 is expressed in hematopoietic cells and localizes to the cytosol. Phosphorylation and activation of HPK1 are dependent on adaptor proteins that link HPK1 to cell surface receptors, such as EGFR, and downstream gene transcription targets, including AP-1, NFAT, and IL-2, to facilitate cell signaling. Low expression of MAP4K1, the gene encoding HPK1, is associated with prolonged survival in patients with renal clear cell carcinoma and low-grade glioma. MAP4K1 expression is decreased in CD4+ T cells isolated from patients with systemic lupus erythematosus (SLE). Cayman's HPK1 (human, recombinant) protein can be used for enzyme activity assays. This protein has a calculated molecular weight of 33. kDa.. Protein function: Serine/threonine-protein kinase, which may play a role in the response to environmental stress (PubMed:24362026). Appears to act upstream of the JUN N-terminal pathway (PubMed:8824585). May play a role in hematopoietic lineage decisions and growth regulation (PubMed:8824585, PubMed:24362026). Able to autophosphorylate (PubMed:8824585). Together with CLNK, it enhances CD3-triggered activation of T-cells and subsequent IL2 production. [The UniProt Consortium]