[Interactions between MAP4K1 and adaptor proteins].

Mitogen-activated protein kinase kinase kinase kinase 1 (MAP4K1, also called hematopoietic progenitor kinase 1, HPK1) is a serine/threonine kinase. As a member of the MAP4K family, MAP4K1 is closely associated with various adaptor proteins such as caspase recruitment domain family member 11 (CARD11), hematopoietic cell-specific protein 1 (HS1), HPK1-interacting protein of 55 kD (HIP-55), growth factor receptor-bound protein 2 (GRB2) family, the linker for activated T-cells (LAT), SH2 domain containing leukocyte protein of 76 kD (SLP-76) family, homologues of the v-crk oncogene product (CRK) family, the B-cell adaptor molecule of 32 kD (BAM32), etc. It plays important roles in many immunoreactions, such as regulation of cellular proliferation and apoptosis, inhibition of TCR/BCR signaling and T/B/dendritic cells-mediated immune responses. Thus, MAP4K1 is involved in autoimmune diseases and plays a key role in tumor and inflammatory reaction.