Clarification of mechanism of anamorsin, anti-apoptotic molecule

我们鉴定了一种名为anamorsin的抗凋亡分子，它与已知的凋亡调控分子或细胞生长相关分子没有任何同源性。Anamorsin在体内被发现是一种抗凋亡分子，因为Anamorsin-/-小鼠由于胎儿肝脏(FL)的最终造血缺陷而在妊娠晚期死亡。Anamorsin被预测为从其氨基酸序列中作为甲基转移酶发挥作用，然而，Anamorsin如何发挥作用的确切机制尚未阐明。为了揭示其作用机制，我们尝试通过酵母双杂交实验寻找与Anamorsin结合的分子。初步鉴定为Picot(类硫氧还蛋白2)。我们已经证明Anamorsn和Picot在体内和体外相互结合。此外，还发现Anamorsin与Picot在11-180位氨基酸(N-末端)结合，而Picot与Anamorsin在18-117位(N-末端)结合。PICOT最初被鉴定为蛋白激酶Cθ(PKCθ)结合蛋白，并被认为能抑制PKCθ活性的细胞生长和存活。Anamorsin可能与PICOT结合，并可能改变PICOT抑制PKCθ的活性。未来，我们将重点研究Anamorsin和Picot在细胞生长和存活中的相互作用。

We identified an anti-apoptotic molecule named anamorsin, which does not show any homology to known apoptosis regulatory molecules or cell growth related molecules. Anamorsin was found to act as an anti-apoptotic molecule in vivo since anamorsin -/- mice die in late gestation due to defective definitive hematopoiesis in the fetal liver (FL). Anamorsin is predicted to work as a methyltransferase from its amino acid sequence, however, the precise mechanisms how anamorsin works have not been clarified. In order to reveal the mechanism, we tried to find the anamorsin binding molecules by yeast-two-hybrid assay. Picot (thioredoxin-like 2) was preferentially identified. We have shown that anamorsn and picot bind each other in vivo and in vitro. Furthermore, it was found that anamorsin binds with picot at 11-180 amino acids (N-terminal) position, while picot binds with anamorsin at 18-117 amino acids (N-terminal) position. Picot was originally identified as protein kinase C θ (PKCθ) binding protein, and thought to inhibit PKCθ activity of cell growth and survival. It is possible that anamorsin binds with picot and might modify picot activity of PKCθ inhibition. In the future, we will focus on reciprocal actions of anamorsin and picot in the cell growth and survival.