Most eukaryotic messenger RNA precursors (pre-mRNAs) must undergo extensive co- transcriptional processing in the nucleus before they can be exported to the cytoplasm and function as mRNAs. The processing events include 5'-end capping, splicing, and 3'- end polyadenylation. The 3'-end polyadenylation of pre-mRNAs occurs in two steps- endonucleolytic cleavage of the pre-mRNA at a specific site near its 3'-end and then the addition of the poly(A) tail. While this process may appear to be simple biochemically, it requires a large number of protein factors for its execution, including cleavage and polyadenylation specificity factor (CSPF), cleavage stimulation factor (CstF), cleavage factors I and II, and poly(A) polymerase (PAP). The CPSF complex contains five subunits, CPSF-30, CPSF-73, CPSF-100, CPSF-160 and Fip1, and the CstF complex contains three subunits, CstF-50, CstF-64, and CstF-77. The 3'-end processing machinery in yeast has similarity to that in mammals, although there are also significant differences. During the previous funding period, we employed a divide-and-conquer approach to examine the various proteins of the mammalian and yeast 3'-end processing machineries on their own, and we have also begun to study their sub-complexes. A major emphasis for the current funding period is the studies on such complexes, which will produce significantly more insight into the molecular mechanism of these machineries. We will use symplekin/Pta1 as a unifying theme for some of these studies, as this scafold protein wil lead us to many other proteins in these machineries. We have determined the crystal structure of symplekin N-terminal domain in a ternary complex with the RNA polymerase II C-terminal domain (CTD) Ser5 phosphatase Ssu72 and a CTD phosphopeptide, illustrating a successful start for research in the current funding period.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Molecular Genetics A Study Section (MGA)
Program Officer
Preusch, Peter C
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Columbia University (N.Y.)
Other Domestic Higher Education
New York
United States
Zip Code
Zhang, Yinglu; Rataj, Katarzyna; Simpson, Gordon G et al. (2016) Crystal Structure of the SPOC Domain of the Arabidopsis Flowering Regulator FPA. PLoS One 11:e0160694
Luo, Shukun; Tong, Liang (2014) Molecular basis for the recognition of methylated adenines in RNA by the eukaryotic YTH domain. Proc Natl Acad Sci U S A 111:13834-9
Wilson, William C; Hornig-Do, Hue-Tran; Bruni, Francesco et al. (2014) A human mitochondrial poly(A) polymerase mutation reveals the complexities of post-transcriptional mitochondrial gene expression. Hum Mol Genet 23:6345-55
Jurado, Ashley R; Tan, Dazhi; Jiao, Xinfu et al. (2014) Structure and function of pre-mRNA 5'-end capping quality control and 3'-end processing. Biochemistry 53:1882-98
Zhang, Jun; Tan, Dazhi; DeRose, Eugene F et al. (2014) Molecular mechanisms for the regulation of histone mRNA stem-loop-binding protein by phosphorylation. Proc Natl Acad Sci U S A 111:E2937-46
Xiang, Kehui; Tong, Liang; Manley, James L (2014) Delineating the structural blueprint of the pre-mRNA 3'-end processing machinery. Mol Cell Biol 34:1894-910
Tan, Dazhi; Zhou, Mi; Kiledjian, Megerditch et al. (2014) The ROQ domain of Roquin recognizes mRNA constitutive-decay element and double-stranded RNA. Nat Struct Mol Biol 21:679-85
Tan, Dazhi; Marzluff, William F; Dominski, Zbigniew et al. (2013) Structure of histone mRNA stem-loop, human stem-loop binding protein, and 3'hExo ternary complex. Science 339:318-21
Xiang, Kehui; Manley, James L; Tong, Liang (2012) An unexpected binding mode for a Pol II CTD peptide phosphorylated at Ser7 in the active site of the CTD phosphatase Ssu72. Genes Dev 26:2265-70
Paulson, Ashley R; Tong, Liang (2012) Crystal structure of the Rna14-Rna15 complex. RNA 18:1154-62

Showing the most recent 10 out of 19 publications