The long-term goal of this project is to improve both the diagnoses and the treatments of Leber congenital amaurosis (LCA). LCA is a set of inherited, early onset retinopathies that affect about 1 in 50,000 in the general U.S. population and accounts for more than 5% of all retinal dystrophies. The molecular basis for LCA is heterogeneous with mutations in 22 different genes that have been associated with the disease. Strikingly, ciliopathy has been identified as one of the major causes of LCA with 25% of the known disease- causing genes involved in proper cilia formation and function in photoreceptor cells. However, despite the large number of retinal disease genes related to cilium function, the precise disease mechanisms remain largely unknown. We have recently identified that Spata7, a ciliopathy gene, maintains a photoreceptor- specific transition zone (PSTZ), which is a specialized structure in photoreceptor connecting cilia and plays a critical role in protein trafficking. In this proposal, we plan to utilize Spata7 as an entry point to better understand the function of this novel PSTZ zone in the connecting cilium of photoreceptor cells.
Our Specific Aims are to:
Specific Aim 1 : Define and characterize two novel zones of the connecting cilium.
Specific Aim 2. Determine the mechanism of SPATA7 action in RPGR complex assembly and function in the distal TZ of photoreceptor cilia.
Specific Aim 3 : Determine the role of Spata7 in PSTZ structure and function. Together these studies will provide a systematic evaluation of the PSTZ structure, key protein composition, regulation, and function, thereby providing novel insights concerning the molecular mechanisms of protein trafficking through the connecting cilium of photoreceptor cells. Given the central role primary cilia play not only in retinal disease, but also many other syndromic pathologies, these aims have the potential to make a high impact in our understanding of and ability to diagnose and treat human disease.

Public Health Relevance

The main goal of this project is to create a model of the human retinal disease called Leber congenital amaurosis (LCA), which is the leading cause of blindness in infants. In order to create more effective means of diagnosis, prevention, and treatment, we need a more detailed understanding of this devastating disease. Our model for LCA using the mouse will provide an essential platform for determining the exact defects and potential therapies to correct such defects.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY020540-05A1
Application #
9384354
Study Section
Biology of the Visual System Study Section (BVS)
Program Officer
Neuhold, Lisa
Project Start
2011-02-01
Project End
2018-09-29
Budget Start
2017-09-30
Budget End
2018-09-29
Support Year
5
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Pathology
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Eblimit, Aiden; Zaneveld, Smriti Agrawal; Liu, Wei et al. (2018) NMNAT1 E257K variant, associated with Leber Congenital Amaurosis (LCA9), causes a mild retinal degeneration phenotype. Exp Eye Res 173:32-43
Eblimit, Aiden; Agrawal, Smriti Akshay; Thomas, Kandace et al. (2018) Conditional loss of Spata7 in photoreceptors causes progressive retinal degeneration in mice. Exp Eye Res 166:120-130
Dharmat, Rachayata; Eblimit, Aiden; Robichaux, Michael A et al. (2018) SPATA7 maintains a novel photoreceptor-specific zone in the distal connecting cilium. J Cell Biol 217:2851-2865
Gui, Shupeng; Rice, Andrew P; Chen, Rui et al. (2017) A scalable algorithm for structure identification of complex gene regulatory network from temporal expression data. BMC Bioinformatics 18:74
Chen, Yong; Zhao, Li; Wang, Yi et al. (2017) SeqCNV: a novel method for identification of copy number variations in targeted next-generation sequencing data. BMC Bioinformatics 18:147
Agrawal, Smriti A; Burgoyne, Thomas; Eblimit, Aiden et al. (2017) REEP6 deficiency leads to retinal degeneration through disruption of ER homeostasis and protein trafficking. Hum Mol Genet 26:2667-2677
Arno, Gavin; Agrawal, Smriti A; Eblimit, Aiden et al. (2016) Mutations in REEP6 Cause Autosomal-Recessive Retinitis Pigmentosa. Am J Hum Genet 99:1305-1315
Zhao, Li; Chen, Yiyun; Bajaj, Amol Onkar et al. (2016) Integrative subcellular proteomic analysis allows accurate prediction of human disease-causing genes. Genome Res 26:660-9
Zhong, H; Eblimit, A; Moayedi, Y et al. (2015) AAV8(Y733F)-mediated gene therapy in a Spata7 knockout mouse model of Leber congenital amaurosis and retinitis pigmentosa. Gene Ther 22:619-27
Eblimit, Aiden; Nguyen, Thanh-Minh T; Chen, Yiyun et al. (2015) Spata7 is a retinal ciliopathy gene critical for correct RPGRIP1 localization and protein trafficking in the retina. Hum Mol Genet 24:1584-601

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