The role of PIAS3 in retinal development

PIAS3在视网膜发育中的作用

• 批准号: 8445620
• 负责人: Seth Blackshaw
• 金额: $ 41.3万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8445620
• 关键词: Address; Binding; Biology; Cell Nucleus; Development; ERCC2 gene; Gene Expression; Genes; Human; In Vitro; Ligase; Maintenance; Mediating; Molecular; Mus; Mutant Strains Mice; PIAS3 Gene; Phenotype; Phosphotransferases; Photoreceptors; Play; Post-Translational Protein Processing; Process; Protein Microchips; Proteins; Proteome; Regulation; Retinal; Retinal Cone; Retinal Photoreceptors; Rhodopsin; Role; Site; Specificity; Testing; Transcription Repressor/Corepressor; Vertebrate Photoreceptors; Work; in vivo; insight; prevent; promoter; protein function; protein transport; public health relevance; research study; retinal neuron; retinal rods; therapy development; transcription factor TFIIH

DESCRIPTION (provided by applicant): Our group has determined that PIAS3-dependent SUMOylation plays a central role in regulating both rod and cone photoreceptor differentiation. However, several critical questions about the function of PIAS3 and protein SUMOylation in photoreceptors still remain unresolved. While protein SUMOylation is essential for photoreceptor viability, our previous work did not determine whether PIAS3 is required for the maturation, maintenance or survival of differentiated photoreceptors. To address this question, we will generate and characterize mutant mice that selectively lack PIAS3 expression in photoreceptors. Second, it is not known how PIAS3-dependent SUMOylation induces NR2E3 to act as a transcriptional repressor when bound to the promoters of cone-specific genes, but does not do so when it bound to the promoters of rod-specific genes. We will test whether the TFIIH-associated proteins ERCC2 and CDK7 might mediate this effect by blocking PIAS3-dependent SUMOylation of NR2E3 when it is bound to the promoters of rod-specific genes. Finally, preliminary studies of SUMO ligase specificity obtained using protein microarrays have suggested that PIAS3 and TOPORS, another E3 SUMO ligase critical for photoreceptor function, may regulate the activity of multiple photoreceptor-specific proteins that function outside the nucleus. We have found that BBS4 is SUMOylated by PIAS3, and propose to study how this process regulates BBSome assembly and rhodopsin transport in vivo. We also plan to investigate whether PIAS3 also regulates the function of other ciliary and centrosomal proteins such as CEP290 through site-specific SUMOylation, and will whether the activity of PIAS3 is controlled by TOPORS-dependent SUMOylation, as suggested by our preliminary in vitro analysis.

描述（由申请人提供）：我们的小组已经确定PIAS 3依赖性SUMO化在调节视杆细胞和视锥细胞的分化中起着重要作用。然而，关于PIAS3和蛋白SUMO化在光感受器中的功能的几个关键问题仍然没有解决。虽然蛋白SUMO化对于光感受器的活力是必不可少的，但我们以前的工作并没有确定PIAS3是否是分化的光感受器的成熟、维持或存活所必需的。为了解决这个问题，我们将产生和表征选择性缺乏PIAS3在光感受器中表达的突变小鼠。其次，目前尚不清楚PIAS3依赖性SUMO化如何诱导NR2E3在与视锥细胞特异性基因的启动子结合时充当转录抑制因子，但在与视杆细胞特异性基因的启动子结合时不这样做。我们将测试TFIIH相关蛋白ERCC 2和CDK 7是否可能通过阻断NR2E3与视杆特异性基因启动子结合时的PIAS 3依赖性SUMO化来介导这种效应。最后，使用蛋白质微阵列获得的SUMO连接酶特异性的初步研究表明，PIAS3和TOPORS，另一个E3 SUMO连接酶的感光功能的关键，可能会调节多种感光细胞特异性蛋白质的活性，细胞核外的功能。我们已经发现BBS4被PIAS3 SUMO化，并建议研究该过程如何调节BBSome组装和体内视紫红质转运。我们还计划研究PIAS3是否也通过位点特异性SUMO化调节其他纤毛和中心体蛋白如CEP290的功能，并将PIAS3的活性是否由TOPORS依赖性SUMO化控制，正如我们初步的体外分析所建议的那样。