Thymopoietin (TMPO) (TMPO)

Thymopoietin (TMPO) is a pleiotropic protein that functions both as a thymic hormone and a structural component of the nuclear envelope (UniProt P42166). Encoded by the TMPO gene, it exists in several isoforms, most notably alpha, beta (also known as LAP2 beta), and gamma, which are generated through alternative splicing (Harris et al., 1994). As a hormone, it is secreted by thymic epithelial cells and is critical for the induction of T-lymphocyte differentiation and the maintenance of immune homeostasis (Goldstein, 1975). In the nucleus, its isoforms play a vital role in organizing nuclear architecture and regulating the cell cycle by interacting with lamins and chromatin (Dechat et al., 2000). Pathologically, the overproduction or systemic release of thymopoietin is associated with Myasthenia Gravis, as it acts as an antagonist at nicotinic acetylcholine receptors, leading to impaired neuromuscular transmission (Quik et al., 1990). Conversely, its synthetic derivative, Thymopentin (TP-5), is used clinically as an immunomodulator to treat various immunodeficiencies and as an adjunct in cancer therapy to bolster the immune response (NCI Drug Dictionary).

Other names

Lamina-associated polypeptide 2LAP2CMD1TLEMD4TPThymopoietin alphaThymopoietin betaThymopoietin gammaThymopoietin IThymopoietin II

Thymopoietin and its synthetic derivative, Thymopentin, act as agonists at specific receptors on T-cell precursors to stimulate differentiation and maturation. In the neuromuscular system, thymopoietin acts as an antagonist at nicotinic acetylcholine receptors (nAChR), inhibiting synaptic transmission.