The nuclear envelope separates the nucleoplasm from the cytoplasm in eukaryotic cells and includes the outer and inner nuclear membrane, nuclear pore complexes and the nuclear lamina. The nuclear lamina contains intermediate filament-type proteins called lamins that form a dense network to strengthen and stabilize the nuclear envelope. Lamina-associated polypeptide 2 (LAP2) is also known as thymopoietin. LAP2 is a nuclear envelope protein and contains an amino-terminal region called the LAP2-emerin-MAN1 or LEM motif. LAP2 also contains a unique DNA-binding amino-terminal domain. Alternative splicing produces six isoforms (i±, i²,i³, iμ and i´) of mammalian LAP2 and three isoforms in Xenopus LAP2. LAP2i± and LAP2i² associate with chromosomal barrier-to-autointegration factor (BAF) and may play a role in stabilizing chromatin structure. LAP2i² also binds to lamin B. LAP2i± is a non-membrane isoform of LAP2 that associates with the internal nucleoskeleton and binds lamin A. The gene encoding human LAP2 maps to chromosome 12q23.1.
Synonyms: Isoforms beta/gamma, Lamina associated polypeptide 2 alpha, Lamina associated polypeptide 2, LAP2, Thymopoietin, Thymopoietin isoform alpha, TMPO, TP alpha, TP, LAP2 alpha, LAP2A_HUMAN.