Hematopoietic SH2 domain-containing protein (HSH2D)

Hematopoietic SH2 domain-containing protein (HSH2D) is an adaptor protein encoded by the HSH2D gene. It is primarily expressed in hematopoietic tissues (e.g., bone marrow, T lymphocytes, spleen, lymph node) and plays a role in signal transduction, immune response modulation, and apoptosis[1][4][5]. Its defining feature is the SH2 (Src homology 2) domain, which enables interactions with proteins involved in tyrosine kinase signaling, particularly downstream of the CD28 co-stimulatory receptor in T-cell activation[2][4][5]. The protein is implicated in immune regulation, wound healing, cell apoptosis, and remodeling of the extracellular matrix. HSH2D has shown altered expression in autoimmune diseases, cancers, and is a determinant of methotrexate resistance in T-cell acute lymphoblastic leukemia, making it a biomarker for these conditions. Major protein-protein interactions include proto-oncogenes like FES and CRK, and the protein seems to modulate the activation of interleukin-2 during T-cell activation[1][4][5][6]. While not a classical drug or antibody target, its functional relevance in immune signaling and disease resistance mechanisms makes it a protein of research interest.

Other names

ALXHematopoietic SH2 proteinAdaptor in lymphocytes of unknown function XHSH2FLJ14886

Modulation of signal transduction (especially in CD28/tyrosine kinase pathways); contributes to methotrexate resistance in T-ALL by affecting IL-2 production and cell proliferation