NF-Y recruitment of TFIID, multiple interactions with histone fold TAFIIs
NF-Y recruitment of TFIID, multiple interactions with histone fold TAFIIs
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DOI：
10.1074/jbc.m103651200
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发表时间：
2002-02-22
影响因子：
4.8
通讯作者：
Mantovani, R
中科院分区：
文献类型：
--
作者：
Frontini, M;Imbriano, C;Mantovani, R
核因子y （NF-Y）三聚体和TFIID含有组蛋白折叠亚基，它们与主要组织相容性复合体II类Ea启动子的CCAAT和启动子元件的结合是转录激活所必需的。通过琼脂糖-电泳迁移率转移试验，我们发现NF-Y以CCAAT依赖性和非依赖性的方式增加了全tfiid对Ea的亲和力。我们开始剖析NF-Y-和tbp相关因子PO1II (TAF(II)s)-含组蛋白折叠结构域在蛋白-蛋白相互作用和转染中的相互作用。hTAF(II)20、hTAF(II)28和hTAF(II)18-hTAF(II)28与NF-Y B-NF-YC组蛋白折叠二聚体结合；hTAF(II)80和hTAF(II)31-hTAF(II)80与三聚体相互作用，但不与NF-YB-NF-YC二聚体相互作用。hTAF(II)80的组蛋白折叠α 2螺旋不是NF-Y关联所必需的，这是通过与自然发生的剪接变体hTAF(II)80delta的相互作用确定的。在基于gal4的实验中，小鼠细胞中表达hTAF(II)28和hTAF(II)18显著特异性地降低了NF-Y的激活，而hTAF、120和hTAF(II)135则增加了NF-Y的激活。这些结果表明，NF-Y (i)在体外招募纯化的holo-TFIID， （ii）可以结合多个TAF(ii) s，可能适应不同的核心启动子结构。
The nuclear factor y (NF-Y) trimer and TFIID contain histone fold subunits, and their binding to the CCAAT and Initiator elements of the major histocompatibility complex class II Ea promoter is required for transcriptional activation. Using agarose-electrophoretic mobility shift assay we found that NF-Y increases the affinity of holo-TFIID for Ea in a CCAAT- and Inr-dependent manner. We began to dissect the interplay between NF-Y- and TBP-associated factors PO1II (TAF(II)s)-containing histone fold domains in protein-protein interactions and transfections. hTAF(II)20, hTAF(II)28, and hTAF(II)18-hTAF(II)28 bind to the NF-Y B-NF-YC histone fold dimer; hTAF(II)80 and hTAF(II)31-hTAF(II)80 interact with the trimer but not with the NF-YB-NF-YC dimer. The histone fold alpha2 helix of hTAF(II)80 is not required for NF-Y association, as determined by interactions with the naturally occurring splice variant hTAF(II)80delta. Expression of hTAF(II)28 and hTAF(II)18 in mouse cells significantly and specifically reduced NF-Y activation in GAL4-based experiments, whereas hTAF,120 and hTAF(II)135 increased it. These results indicate that NF-Y (i) recruits purified holo-TFIID in vitro and (ii) can associate multiple TAF(II)s, potentially accommodating different core promoter architectures.