HCLS1 Protein, Human (HEK293, His)

HCLS1, a substrate of the antigen receptor-coupled tyrosine kinase, plays a pivotal role in antigen receptor signaling, influencing both clonal expansion and deletion in lymphoid cells. Beyond its involvement in signaling cascades, HCLS1 may contribute to the regulation of gene expression. The protein forms associations with the SH2 and SH3 domains of LCK, with binding to the LCK SH3 domain being constitutive, and binding to the LCK SH2 domain occurring exclusively upon T-cell receptor (TCR) stimulation. Similar binding patterns were observed with LYN, contrasting with FYN, where the FYN SH2 region associates upon TCR stimulation, while the FYN SH3 region does not, regardless of TCR stimulation. HCLS1 further directly associates with HAX1, particularly through binding to its C-terminal region, and interacts with HS1BP3. Notably, HCLS1 forms a multiprotein complex with LYN and ANKRD54, emphasizing its intricate involvement in signaling networks. Interactions with FES/FPS and FGR add to the complexity of HCLS1's functional associations.