La protein and the trafficking of nascent RNA polymerase iii transcripts.
La protein and the trafficking of nascent RNA polymerase iii transcripts.
复制标题
DOI：
10.1083/jcb.153.4.f13
复制
发表时间：
2001-05-14
期刊：
影响因子：
--
通讯作者：
Maraia RJ
中科院分区：
文献类型：
--
作者：
Maraia RJ
几种小的核和细胞质RNA由RNA聚合酶（Pol）1 III合成为新生转录物，然后必须通过RNA加工，修饰和运输机制迁移，成为成熟的功能分子。与新合成的Pol III转录本相互作用的第一个因子是La蛋白。证据表明，这种分子伴侣伴随着前体tRNA通过各种RNA修饰和加工事件，并促进其他转录成特定的RNP的组装进行审查。虽然大多数La是核质，一些是核仁，和几个Pol III转录，包括前体的tRNA，U6小核RNA（snRNA），RNase P RNA，和信号识别颗粒（SRP）RNA，最近已被证明通过核仁移动。先前在La相关的U6 snRNA上发现的修饰，加上最近的数据，现在表明这些修饰发生在核仁中，而U6 RNA与La相关。最后，数据表明，人类La表现出两步模式的RNA结合，是敏感的磷酸化进行审查，这种模式的结合的影响被认为是在背景下的动态RNA成熟。RNA Pol III合成许多小RNA，包括5S核糖体rRNA和tRNA、U6和RNase P snRNA、MRP小核仁RNA（snoRNA）以及SRP和Y小细胞质RNA家族。与Pol I和II的转录物类似，新合成的Pol III转录物经历涉及核苷酸的去除、修饰和添加的成熟过程。一些Pol III转录本几乎不进行加工，而另一些则进行广泛的加工。前体tRNA经历复杂的核内成熟过程，该过程涉及在转运到细胞质之前被许多切割和修饰酶识别（Wolin和Matera，1999）。
Several small nuclear and cytoplasmic RNAs are synthesized by RNA polymerase (Pol) 1 III as nascent transcripts that must then migrate through RNA processing, modification, and transport machinery on their trek to becoming mature, functional molecules. The first factor to interact with newly synthesized Pol III transcripts is the La protein. Evidence that this molecular chaperone accompanies precursor tRNAs through various RNA modification and processing events and facilitates the assembly of other transcripts into specific RNPs is reviewed. Although most La is nucleoplasmic, some is nucleolar, and several Pol III transcripts, including precursors of tRNAs, U6 small nuclear RNA (snRNA), RNase P RNA, and signal recognition particle (SRP) RNA, have recently been shown to move through the nucleolus. Modifications found previously on La-associated U6 snRNA, coupled with recent data, now suggest that these modifications occur in the nucleolus, while U6 RNA is associated with La. Finally, data which indicate that human La exhibits a two-step mode of RNA binding that is sensitive to phosphorylation are reviewed, and the implications of this mode of binding are considered in the context of the dynamics of RNA maturation. RNA Pol III synthesizes many small RNAs, including 5S ribosomal rRNA and tRNAs, U6 and RNase P snRNAs, MRP small nucleolar RNA (snoRNA), as well as SRP and the family of Y small cytoplasmic RNAs. Similar to transcripts of Pols I and II, newly synthesized Pol III transcripts are subjected to a maturation process that involves removal, modification, and addition of nucleotides. Some Pol III transcripts undergo little, while others undergo extensive, processing. Precursor tRNAs endure an elaborate intranuclear maturation process that involves recognition by many cleavage and modification enzymes before transport to the cytoplasm (Wolin and Matera, 1999).
登录
查看更多内容
DOI：
10.1083/jcb.91.3.654
发表时间：
1981-12
期刊：
The Journal of cell biology
影响因子：
--
作者：
Deng JS;Takasaki Y;Tan EM
通讯作者：
Tan EM
影响因子：
10.5
作者：
Bertrand, E;Houser-Scott, F;Engelke, DR
通讯作者：
Engelke, DR
影响因子：
11.4
作者：
Grimm, C;Lund, E;Dahlberg, JE
通讯作者：
Dahlberg, JE
DOI：
10.1083/jcb.131.6.1649
发表时间：
1995-12
期刊：
The Journal of cell biology
影响因子：
--
作者：
Jacobson MR;Cao LG;Wang YL;Pederson T
通讯作者：
Pederson T
影响因子：
10.5
作者：
Anderson, J;Phan, L;Hinnebusch, AG
通讯作者：
Hinnebusch, AG