Activities of adenovirus virus-associated RNAs: Purification and characterization of RNA binding proteins
Activities of adenovirus virus-associated RNAs: Purification and characterization of RNA binding proteins
复制标题
DOI：
10.1073/pnas.95.15.8514
复制
发表时间：
1998-07-21
影响因子：
11.1
通讯作者：
Mathews, MB
中科院分区：
文献类型：
--
作者：
Liao, HJ;Kobayashi, R;Mathews, MB
大多数人腺病毒编码两种病毒相关（VA）RNA，VA RNA（I）和VA RNA（II），其在感染细胞的细胞质中积累至高水平。VA RNA（I）在阻断细胞激酶PKR活化中的功能是众所周知的，但VA RNA（II）的作用是模糊的。在这里，我们的特点和纯化几个人的蛋白质，相互作用优先与VA RNA（II）在西北印迹分析。其中两种蛋白被鉴定为RNA解旋酶A和NF 90，NF 90是活化T细胞异二聚体核因子（NFAT）的组分。它们与较小的NFAT亚基NF 45共纯化，NF 45不结合VA RNA（II），与未鉴定的蛋白p97共纯化，p97结合VA RNA（II）。RNA解旋酶A和NF 90都含有两个拷贝的双链（ds）RNA结合基序，并与dsRNA强烈结合。NF 90与RNA的相互作用的亲和力顺序如下：dsRNA > VA RNA（II）> VA RNA（I）>单链RNA。此外，VA RNA（II）作为RNA解旋酶活性的抑制剂比VA RNA（I）更有效。这些数据将RNA解旋酶A和NF 90鉴定为对dsRNA和其他结构化RNA分子具有亲和力的细胞蛋白，并表明它们的功能受到包括VA RNA（II）的RNA配体的调节。
Most human adenoviruses encode two virus-associated (VA) RNAs, VA RNA(I) and VA RNA(II), that accumulate to high levels in the cytoplasm of infected cells. The function of VA RNA(I) in blocking the activation of the cellular kinase PKR is well known, but the role of VA RNA(II) is obscure. Herein we characterize and purify several human proteins that interact preferentially with VA RNA(II) in Northwestern blot assays. Two of these proteins were identified as RNA helicase A and NF90, a component of the heterodimeric nuclear factor of activated T cells (NFAT), They copurified with the smaller NFAT subunit, NF45, which did not bind VA RNA(II), and with an unidentified protein, p97, which did bind VA RNA(II). Both RNA helicase A and NF90 contain two copies of a double-stranded (ds) RNA binding motif and bind strongly to dsRNA. NF90 interacts with RNAs in the following order of affinity: dsRNA > VA RNA(II) > VA RNA(I) > single-stranded RNA. Furthermore, VA RNA(II) is more effective than VA RNA(I) as an inhibitor of RNA helicase activity, These data identify RNA helicase A and NF90 as cellular proteins with an affinity for dsRNA and other structured RNA molecules and suggest that their functions are subject to regulation by RNA ligands including VA RNA(II).