Lymphocyte Specific Protein 1 (LSP1)

Lymphocyte-specific protein 1 is an intracellular F-actin binding protein. The protein is expressed in lymphocytes, neutrophils, macrophages, and endothelium and may regulate neutrophil motility, adhesion to fibrinogen matrix proteins, and transendothelial migration. Alternative splicing results in multiple transcript variants encoding different isoforms.

May et al. (1993) and others used various cDNA cloning strategies to identify genes preferentially expressed in B lymphocytes. One gene, variously named LSP1 and pp52, exhibited a number of properties supporting a possible role in B-cell signaling pathways. The gene codes for a 52-kD phosphoprotein expressed only in transformed and untransformed B cells, thymocytes, and untransformed T-cell lines.