Verreault A, Kaufman P D, Kobayashi R, Stillman B
Cold Spring Harbor Laboratory, New York 11724, USA.
Cell. 1996 Oct 4;87(1):95-104. doi: 10.1016/s0092-8674(00)81326-4.
Chromatin assembly factor 1 (CAF-1) assembles nucleosomes in a replication-dependent manner. The small subunit of CAF-1 (p48) is a member of a highly conserved subfamily of WD-repeat proteins. There are at least two members of this subfamily in both human (p46 and p48) and yeast cells (Hat2p, a subunit of the B-type H4 acetyltransferase, and Msi1p). Human p48 can bind to histone H4 in the absence of CAF-1 p150 and p60. p48, also a known subunit of a histone deacetylase, copurifies with a chromatin assembly complex (CAC), which contains the three subunits of CAF-1 (p150, p60, p48) and H3 and H4, and promotes DNA replication-dependent chromatin assembly. CAC histone H4 exhibits a novel pattern of lysine acetylation that overlaps with, but is distinct from, that reported for newly synthesized H4 isolated from nascent chromatin. Our data suggest that CAC is a key intermediate of the de novo nucleosome assembly pathway and that the p48 subunit participates in other aspects of histone metabolism.
染色质组装因子1（CAF-1）以复制依赖的方式组装核小体。CAF-1的小亚基（p48）是WD重复蛋白高度保守亚家族的成员。在人类（p46和p48）和酵母细胞（Hat2p，B型H4乙酰转移酶的一个亚基，以及Msi1p）中，这个亚家族至少有两个成员。在没有CAF-1 p150和p60的情况下，人类p48能与组蛋白H4结合。p48也是一种已知的组蛋白去乙酰化酶的亚基，它与一种染色质组装复合物（CAC）共纯化，该复合物包含CAF-1的三个亚基（p150、p60、p48）以及H3和H4，并促进DNA复制依赖的染色质组装。CAC组蛋白H4呈现出一种新的赖氨酸乙酰化模式，该模式与从新生染色质中分离出的新合成H4的模式重叠，但又有所不同。我们的数据表明，CAC是从头组装核小体途径的关键中间体，并且p48亚基参与组蛋白代谢的其他方面。
