From the Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109.
From the Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109
J Biol Chem. 2018 Sep 14;293(37):14569-14570. doi: 10.1074/jbc.H118.005247.
Labile heme, as opposed to heme that is tightly bound within proteins, is thought to require a chaperone to be trafficked within the cell due to its cytotoxicity, but the identity of this chaperone was not known. A new study reveals that an unlikely protein, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), is a heme chaperone that binds and transfers labile heme to downstream target proteins. These results provide a new framework for understanding heme homeostasis and raise intriguing questions regarding the intersection of heme transport, carbohydrate metabolism, and intracellular signaling.
不稳定血红素与紧密结合在蛋白质内的血红素不同，由于其细胞毒性，被认为需要伴侣蛋白在细胞内运输，但这种伴侣蛋白的身份尚不清楚。一项新的研究表明，一种不太可能的蛋白质——甘油醛-3-磷酸脱氢酶（GAPDH）——是一种血红素伴侣蛋白，它可以结合并将不稳定的血红素转移到下游靶蛋白上。这些结果为理解血红素稳态提供了一个新的框架，并提出了关于血红素运输、碳水化合物代谢和细胞内信号转导交叉的有趣问题。
