Protein trafficking is a fundamental biological process across all eukaryotic cells. A central question in cell physiology is how the cell manages to accommodate the trafficking of a plethora of cargoes with a very limited number of motor proteins. A wide variety of modulators mediate the intracellular transport of a plethora of endogenous cargoes between subcellular compartments, and pathogens often hijack components of this transport machinery. Emerging evidence also supports this process is vital for triggering defined cellular events such as the onset of mitosis and cell death. Protein kinesis assumes special relevance in neuronal systems in light of the exquisite compartmentalization and polarization of subcellular compartments and organelles across neurons, and significant burden imposed on neurons for the long distances cargoes often need to travel to reach their final destinations. A large and growing number of genetic lesions in trafficking components and interacting cargoes, lead to a host of neuropathies and allied maladies in the human. In this proposal, the neuroretina is the experimental system of choice to study protein kinesis because it is a diverse but extremely well defined biological system highly amenable to manipulations in vitro and in vivo. In addition, there are a large number of neurodegenerative retinal dystrophies, which affect directly and indirectly numerous facets of processes mediating protein trafficking. The focus of this proposal is to understand the role of an unique and large scaffold vertebrate protein, Ran-binding protein 2 (RanBP2/Nup358), in mediating and integrating key steps of intracellular trafficking processes and protein biogenesis, and implications of these processes in retinal cell physiology and etiology of pathological states. Past work has implicated RanBP2 in mediating in vivo the functional production of light-receptors and nuclear protein import. We have mapped and characterized domains of RanBP2, identified associated molecular partners and determined the spatial localization of these among and within retinal neurons. Moreover, a large number of molecular, biochemical, immunological and genetic tools were developed. These, in combination with other interdisciplinary approaches, will now be used to probe in vitro and in vivo specific and emerging trafficking pathways mediated by RanBP2 within retinal neurons, to identify novel partners and cargoes, regulatory mechanisms modulating the assembly of RanBP2 complexes, and to dissect further the molecular basis of neuronal-restricted transport pathways mediated by RanBP2. Finally, we will investigate the physiological effects of these components and processes in the pathogenesis of retinal dystrophies.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY011993-05A1
Application #
6775962
Study Section
Synapses, Cytoskeleton and Trafficking Study Section (SYN)
Program Officer
Mariani, Andrew P
Project Start
1999-08-01
Project End
2007-04-30
Budget Start
2004-05-01
Budget End
2005-04-30
Support Year
5
Fiscal Year
2004
Total Cost
$340,594
Indirect Cost
Name
Medical College of Wisconsin
Department
Pharmacology
Type
Schools of Medicine
DUNS #
937639060
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Cho, K-in; Yi, H; Yeh, A et al. (2009) Haploinsufficiency of RanBP2 is neuroprotective against light-elicited and age-dependent degeneration of photoreceptor neurons. Cell Death Differ 16:287-97
Cho, Kyoung-in; Yi, Haiqing; Desai, Ria et al. (2009) RANBP2 is an allosteric activator of the conventional kinesin-1 motor protein, KIF5B, in a minimal cell-free system. EMBO Rep 10:480-6
Moore, David F; Gelderman, Monique P; Ferreira, Paulo A et al. (2007) Genomic abnormalities of the murine model of Fabry disease after disease-related perturbation, a systems biology approach. Proc Natl Acad Sci U S A 104:8065-70
Cho, Kyoung-in; Cai, Yunfei; Yi, Haiqing et al. (2007) Association of the kinesin-binding domain of RanBP2 to KIF5B and KIF5C determines mitochondria localization and function. Traffic 8:1722-35
Yi, Haiqing; Friedman, Julie L; Ferreira, Paulo A (2007) The cyclophilin-like domain of Ran-binding protein-2 modulates selectively the activity of the ubiquitin-proteasome system and protein biogenesis. J Biol Chem 282:34770-8
Aslanukov, Azamat; Bhowmick, Reshma; Guruju, Mallikarjuna et al. (2006) RanBP2 modulates Cox11 and hexokinase I activities and haploinsufficiency of RanBP2 causes deficits in glucose metabolism. PLoS Genet 2:e177
Lu, Xinrong; Ferreira, Paulo A (2005) Identification of novel murine- and human-specific RPGRIP1 splice variants with distinct expression profiles and subcellular localization. Invest Ophthalmol Vis Sci 46:1882-90
Ferreira, Paulo A (2005) Insights into X-linked retinitis pigmentosa type 3, allied diseases and underlying pathomechanisms. Hum Mol Genet 14 Spec No. 2:R259-67
Lu, Xinrong; Guruju, Mallikarjuna; Oswald, John et al. (2005) Limited proteolysis differentially modulates the stability and subcellular localization of domains of RPGRIP1 that are distinctly affected by mutations in Leber's congenital amaurosis. Hum Mol Genet 14:1327-40
Roepman, Ronald; Letteboer, Stef J F; Arts, Heleen H et al. (2005) Interaction of nephrocystin-4 and RPGRIP1 is disrupted by nephronophthisis or Leber congenital amaurosis-associated mutations. Proc Natl Acad Sci U S A 102:18520-5

Showing the most recent 10 out of 18 publications