Skaar David A, Greenleaf Arno L
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
Mol Cell. 2002 Dec;10(6):1429-39. doi: 10.1016/s1097-2765(02)00731-1.
There are several kinases in Saccharomyces cerevisiae that phosphorylate the CTD of RNA polymerase II, but specific and distinct functions of the phospho-CTDs generated by the different kinases are not well understood. A genetic screen for suppressors of loss of yeast CTD kinase I (CTDK-I) function (by deletion of the catalytic subunit gene CTK1) identified PTI1, a potential 3' cleavage/polyadenylation factor. Genetic and physical interactions connect Pti1p to components of CF IA and CF II/CPF, and mutations of PTI1 or CTK1 affect 3' cleavage site choice and transcript abundance of particular genes. Therefore, one important function of the CTDK-I-generated phospho-CTD appears to be the coupling of transcription to 3' processing of pre-mRNAs by a Pti1p-containing complex.
酿酒酵母中有几种激酶可磷酸化RNA聚合酶II的CTD,但不同激酶产生的磷酸化CTD的特定且独特的功能尚未得到充分了解。对酵母CTD激酶I(CTDK-I)功能丧失(通过缺失催化亚基基因CTK1)的抑制子进行的遗传筛选鉴定出了PTI1,一种潜在的3'切割/聚腺苷酸化因子。遗传和物理相互作用将Pti1p与CF IA和CF II/CPF的组分联系起来,PTI1或CTK1的突变会影响特定基因的3'切割位点选择和转录本丰度。因此,CTDK-I产生的磷酸化CTD的一个重要功能似乎是通过一个含Pti1p的复合物将转录与前体mRNA的3'加工偶联起来。