Human Molecular Genetics Advance Access originally published online on March 30, 2005
Human Molecular Genetics 2005 14(10):1327-1340; doi:10.1093/hmg/ddi143
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Limited proteolysis differentially modulates the stability and subcellular localization of domains of RPGRIP1 that are distinctly affected by mutations in Leber's congenital amaurosis
Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
* To whom correspondence should be addressed. Tel: +1 4144568877; Fax: +1 4144566545; Email: ferreira{at}mcw.edu
Received February 2, 2005; Revised March 15, 2005; Accepted March 23, 2005
The retinitis pigmentosa GTPase regulator (RPGR) protein interacts with the retinitis pigmentosa GTPase regulator interacting protein-1 (RPGRIP1). Genetic lesions in the cognate genes lead to distinct and severe human retinal dystrophies. The biological role of these proteins in retinal function and pathogenesis of retinal diseases is elusive. Here, we present the first physiological assay of the role of RPGRIP1 and mutations therein. We found that the monoallelic and homozygous mutations, 
E1279 and D1114G, in the RPGR-interacting domain (RID) of RPGRIP1, enhance and abolish, respectively, its interaction in vivo with RPGR without affecting the stability of RID. In contrast to RIDWT and RIDD1114G, chemical genetics shows that the interaction of RIDE1279 with RPGR is resistant to various stress treatments such as osmotic, pH and heat-shock stimuli. Hence, RIDD1114G and RIDE1279 constitute loss- and gain-of-function mutations. Moreover, we find that the isoforms, bRPGRIP1 and bRPGRIP1b, undergo limited proteolysis constitutively in vivo in the cytoplasm compartment. This leads to the relocation and accumulation of a small and stable N-terminal domain of 
7 kDa to the nucleus, whereas the cytosolic C-terminal domain of RPGRIP1 is degraded and short-lived. The RIDD1114G and RIDE1279 mutations exhibit strong cis-acting and antagonistic biological effects on the nuclear relocation, subcellular distribution and proteolytic cleavage of RPGRIP1 and/or domains thereof. These data support distinct and spatiotemporal subcellular-specific roles to RPGRIP1. A novel RPGRIP1-mediated nucleocytoplasmic crosstalk and transport pathway regulated by RID, and hence by RPGR, emerges with implications in the molecular pathogenesis of retinopathies, and a model to other diseases.
Address after June 1, 2005: Departments of Ophthalmology and Molecular Genetics and Microbiology, Duke University Medical Center, Erwin Road, Durham, NC 27710, USA. Email: ferre044{at}mc.duke.edu
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  E. Vallespin, D. Cantalapiedra, R. Riveiro-Alvarez, R. Wilke, J. Aguirre-Lamban, A. Avila-Fernandez, M. A. Lopez-Martinez, A. Gimenez, M. Jose Trujillo-Tiebas, C. Ramos, et al. Mutation Screening of 299 Spanish Families with Retinal Dystrophies by Leber Congenital Amaurosis Genotyping Microarray Invest. Ophthalmol. Vis. Sci., December 1, 2007; 48(12): 5653 - 5661. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. F. Moore, M. P. Gelderman, P. A. Ferreira, S. R. Fuhrmann, H. Yi, A. Elkahloun, L. M. Lix, R. O. Brady, R. Schiffmann, and E. Goldin Genomic abnormalities of the murine model of Fabry disease after disease-related perturbation, a systems biology approach PNAS, May 8, 2007; 104(19): 8065 - 8070. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Roepman, S. J. F. Letteboer, H. H. Arts, S. E. C. van Beersum, X. Lu, E. Krieger, P. A. Ferreira, and F. P. M. Cremers Interaction of nephrocystin-4 and RPGRIP1 is disrupted by nephronophthisis or Leber congenital amaurosis-associated mutations PNAS, December 20, 2005; 102(51): 18520 - 18525. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. A. Ferreira Insights into X-linked retinitis pigmentosa type 3, allied diseases and underlying pathomechanisms Hum. Mol. Genet., October 15, 2005; 14(suppl_2): R259 - R267. [Abstract] [Full Text] [PDF]
|
|