Emelyanov Alexander V, Fyodorov Dmitry V
Albert Einstein College of Medicine, Department of Cell Biology, Bronx, New York 10461, USA.
Genes Dev. 2016 Dec 15;30(24):2651-2656. doi: 10.1101/gad.290916.116. Epub 2016 Dec 28.
Cysteine oxidation in protamines leads to their oligomerization and contributes to sperm chromatin compaction. Here we identify the Drosophila thioredoxin Deadhead (DHD) as the factor responsible for the reduction of intermolecular disulfide bonds in protamines and their eviction from sperm during fertilization. Protamine chaperone TAP/p32 dissociates DNA-protamine complexes in vitro only when protamine oligomers are first converted to monomers by DHD. dhd-null embryos cannot decondense sperm chromatin and terminate development after the first pronuclear division. Therefore, the thioredoxin DHD plays a critical role in early development to facilitate the switch from protamine-based sperm chromatin structures to the somatic nucleosomal chromatin.
鱼精蛋白中的半胱氨酸氧化导致其寡聚化，并有助于精子染色质的压缩。在这里，我们确定果蝇硫氧还蛋白Deadhead（DHD）是负责还原鱼精蛋白中分子间二硫键并在受精过程中将其从精子中排出的因子。鱼精蛋白伴侣TAP/p32仅在鱼精蛋白寡聚体首先被DHD转化为单体后，才能在体外解离DNA-鱼精蛋白复合物。dhd基因缺失的胚胎无法使精子染色质解聚，并在第一次原核分裂后终止发育。因此，硫氧还蛋白DHD在早期发育中起着关键作用，以促进从基于鱼精蛋白的精子染色质结构向体细胞核小体染色质的转变。
