Sumoylation activates the transcriptional activity of Pax-6, an important transcription factor for eye and brain development

Qin Yan, Lili Gong, Mi Deng, Lan Zhang, Shuming Sun, Jiao Liu, Haili Ma, Dan Yuan, Pei Chao Chen, Xiaohui Hu, Jinping Liu, Jichao Qin, Ling Xiao, Xiao Qin Huang, Jian Zhang, David Wan Cheng Li

Research output: Contribution to journalArticlepeer-review

88 Scopus citations


Pax-6 is an evolutionarily conserved transcription factor regulating brain and eye development. Four Pax-6 isoforms have been reported previously. Although the longer Pax-6 isoforms (p46 and p48) bear two DNA-binding domains, the paired domain (PD) and thehomeodomain (HD), the shorter Pax-6 isoform p32 contains only theHDforDNAbinding.Althoughathirddomain, theproline-, serineand threonine-enriched activation (PST) domain, in the C termini of all Pax-6 isoforms mediates their transcriptional modulation via phosphorylation, howp32 Pax-6 could regulate target genes remains to be elucidated. In the present study, we show that sumoylation at K91 is required for p32 Pax-6 to bind to a HD-specific site and regulate expression of target genes. First, in vitro-synthesized p32 Pax-6 alone cannot bind the P3 sequence, which contains the HD recognition site, unless it is preincubated with nuclear extracts precleared by anti-Pax-6 but not by anti-small ubiquitin-related modifier 1 (anti-SUMO1) antibody. Second, in vitro-synthesized p32 Pax-6 can be sumoylated by SUMO1, and the sumoylated p32 Pax-6 then can bind to the P3 sequence. Third, Pax-6 andSUMO1are colocalized in the embryonic optic and lens vesicles and can be coimmunoprecipitated. Finally, SUMO1-conjugated p32 Pax-6 exists in both the nucleus and cytoplasm, and sumoylation significantly enhances the DNA-binding ability of p32 Pax-6 and positively regulates gene expression. Together, our results demonstrate that sumoylation activates p32 Pax-6 in both DNA-binding and transcriptional activities. In addition, our studies demonstrate that p32 and p46 Pax-6 possess differential DNA-binding and regulatory activities.

Original languageEnglish (US)
Pages (from-to)21034-21039
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number49
StatePublished - Dec 7 2010


  • Cataract
  • Lens
  • Pancreas
  • Retina
  • Small eye mutation

ASJC Scopus subject areas

  • General


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