Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Medicine and Health Sciences
Multisite Phosphorylation Of The Sum1 Transcriptional Repressor By S-Phase Kinases Controls Exit From Meiotic Prophase In Yeast., Daniel Corbi, Sham Sunder, Michael Weinreich, Aikaterini Skokotas, Erica S Johnson, Edward Winter
Multisite Phosphorylation Of The Sum1 Transcriptional Repressor By S-Phase Kinases Controls Exit From Meiotic Prophase In Yeast., Daniel Corbi, Sham Sunder, Michael Weinreich, Aikaterini Skokotas, Erica S Johnson, Edward Winter
Department of Biochemistry and Molecular Biology Faculty Papers
Activation of the meiotic transcription factor Ndt80 is a key regulatory transition in the life cycle of Saccharomyces cerevisiae because it triggers exit from pachytene and entry into meiosis. The NDT80 promoter is held inactive by a complex containing the DNA-binding protein Sum1 and the histone deacetylase Hst1. Meiosis-specific phosphorylation of Sum1 by the protein kinases Cdk1, Ime2, and Cdc7 is required for NDT80 expression. Here, we show that the S-phase-promoting cyclin Clb5 activates Cdk1 to phosphorylate most, and perhaps all, of the 11 minimal cyclin-dependent kinase (CDK) phospho-consensus sites (S/T-P) in Sum1. Nine of these sites can individually promote …
The P53-Induced Factor Ei24 Inhibits Nuclear Import Through An Importin Β-Binding-Like Domain., Kim G Lieu, Eun-Hee Shim, Jinling Wang, Ravi K Lokareddy, Tao Tao, Gino Cingolani, Gerard P Zambetti, David A Jans
The P53-Induced Factor Ei24 Inhibits Nuclear Import Through An Importin Β-Binding-Like Domain., Kim G Lieu, Eun-Hee Shim, Jinling Wang, Ravi K Lokareddy, Tao Tao, Gino Cingolani, Gerard P Zambetti, David A Jans
Department of Biochemistry and Molecular Biology Faculty Papers
The etoposide-induced protein Ei24 was initially identified as a p53-responsive, proapoptotic factor, but no clear function has been described. Here, we use a nonbiased proteomics approach to identify members of the importin (IMP) family of nuclear transporters as interactors of Ei24 and characterize an IMPβ-binding-like (IBBL) domain within Ei24. We show that Ei24 can bind specifically to IMPβ1 and IMPα2, but not other IMPs, and use a mutated IMPβ1 derivative to show that Ei24 binds to the same site on IMPβ1 as the IMPα IBB. Ectopic expression of Ei24 reduced the extent of IMPβ1- or IMPα/β1-dependent nuclear protein import specifically, …