Adams C R, Kamakaka R T
Unit on Chromatin and Transcription, National Institute of Child Health and Human Development, Bldg. 18T, Room 106, 18 Library Drive, Bethesda, Maryland 20892, USA.
Curr Opin Genet Dev. 1999 Apr;9(2):185-90. doi: 10.1016/S0959-437X(99)80028-8.
Investigations on chromatin assembly in vitro implicate chromatin assembly factor 1 (CAF1) as a chaperone for histones H3/H4 and nucleosome assembly protein 1 (NAP1) as a chaperone for histones H2A/H2B. Deletion analysis of CAF1 in vivo suggests multiple redundant pathways for deposition of the histones. Histone deposition requires acetylation of the amino-terminal tails and analysis of mutants suggests a specific but redundant role for acetylation of the tails in assembly. Furthermore, studies on the HAT1 acetyltransferase raise the possibility that acetylation of histones occurs following their transport into the nucleus but prior to their deposition onto DNA. Identification of the factors involved in the redundant pathways of assembly is awaited.
体外染色质组装研究表明，染色质组装因子1（CAF1）作为组蛋白H3/H4的伴侣蛋白，而核小体组装蛋白1（NAP1）作为组蛋白H2A/H2B的伴侣蛋白。体内CAF1的缺失分析表明，组蛋白沉积存在多条冗余途径。组蛋白沉积需要氨基末端尾巴的乙酰化，对突变体的分析表明尾巴乙酰化在组装过程中具有特定但冗余的作用。此外，对HAT1乙酰转移酶的研究提出了一种可能性，即组蛋白的乙酰化发生在它们转运到细胞核之后但沉积到DNA之前。尚待确定参与组装冗余途径的因子。
