LEM (Lap2/Emerin/Man1) domain found in lamina-associated polypeptide 2 (LAP2), LEM domain-containing protein 1 (LEMP-1) and similar proteins
This CD corresponds to the LEM domain of LAP2, LEMP-1 and similar proteins. LAP2, also termed thymopoietin (TP), or thymopoietin-related peptide (TPRP), is composed of isoform alpha and isoforms beta/gamma and may be involved in chromatin organization and post-mitotic reassembly. Some of LAP2 isoforms are inner nuclear membrane proteins that can bind to nuclear lamins and chromatin, while others are non-membrane nuclear polypeptides. All LAP2 isoforms contain an N-terminal LEM domain that is connected to a highly divergent LEM-like domain by an unstructured linker. Although LEM and LEM-like domains share the same structural fold composed of two large parallel alpha helices, the biochemical nature of the solvent-accessible residues is completely different, indicating that the two domains may target different protein surfaces. The LEM domain interacts with the nonspecific DNA binding protein barrier-to-autointegration factor (BAF) while the LEM-like domain is involved in chromosome binding. LEMP-1, also termed cancer/testis antigen 50 (CT50), is encoded by LEMD1, a novel testis-specific gene expressed in colorectal cancers. It may function as a cancer-testis antigen for immunotherapy of colorectal carcinoma (CRC). LEMP-1 contains an N-terminal LEM domain.