Pin1-mediated Sp1 phosphorylation by CDK1 increases Sp1 stability and decreases its DNA-binding activity during mitosis

Hang Che Yang, Jian Ying Chuang, Wen Yih Jeng, Chia I. Liu, Andrew H J Wang, Pei Jung Lu, Wen Chang Chang, Jan Jong Hung

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We have shown that Sp1 phosphorylation at Thr739 decreases its DNA-binding activity. In this study, we found that phosphorylation of Sp1 at Thr739 alone is necessary, but not sufficient for the inhibition of its DNA-binding activity during mitosis. We demonstrated that Pin1 could be recruited to the Thr739(p)-Pro motif of Sp1 to modulate the interaction between phospho-Sp1 and CDK1, thereby facilitating CDK1-mediated phosphorylation of Sp1 at Ser720, Thr723 and Thr737 during mitosis. Loss of the Cterminal end of Sp1 (amino acids 741-785) significantly increased Sp1 phosphorylation, implying that the C-terminus inhibits CDK1-mediated Sp1 phosphorylation. Binding analysis of Sp1 peptides to Pin1 by isothermal titration calorimetry indicated that Pin1 interacts with Thr739(p)-Sp1 peptide but not with Thr739-Sp1 peptide. X-ray crystallography data showed that the Thr739(p)-Sp1 peptide occupies the active site of Pin1. Increased Sp1 phosphorylation by CDK1 during mitosis not only stabilized Sp1 levels by decreasing interaction with ubiquitin E3-ligase RNF4 but also caused Sp1 to move out of the chromosomes completely by decreasing its DNA-binding activity, thereby facilitating cell cycle progression. Thus, Pin1-mediated conformational changes in the C-terminal region of Sp1 are critical for increased CDK1-mediated Sp1 phosphorylation to facilitate cell cycle progression during mitosis.

Original languageEnglish
Pages (from-to)13573-13587
Number of pages15
JournalNucleic Acids Research
Volume42
Issue number22
DOIs
Publication statusPublished - Dec 16 2014

ASJC Scopus subject areas

  • Genetics

Fingerprint Dive into the research topics of 'Pin1-mediated Sp1 phosphorylation by CDK1 increases Sp1 stability and decreases its DNA-binding activity during mitosis'. Together they form a unique fingerprint.

  • Cite this