Cataract is a major cause of blindness in the world. A majority of the cataracts develop due to the age-related modifications and aggregation of the eye lens proteins. Alpha-crystallin accounts for nearly 40 percent of the adult lens proteins. In spite of the intense investigations of the past, the structure-function of alpha-crystallin is not fully understood. Nearly a decade ago the chaperone-like activity of alpha-crystallin was discovered but we are yet to fully understand the molecular mechanism of chaperone activity. There is also growing evidence supporting the interaction of beta- and gamma-crystallins with alpha-crystallin in aging lenses and this interaction has been attributed in part to the chaperone activity of alpha-crystallin. Understanding the alpha-crystallin structure and the molecular mechanism of its chaperone action will enable us to define the mechanisms of cataractogenesis and devise methods to delay/stop the process. The overall goal of our research is to get an insight to alpha-crystallin structure-function and understand the molecular mechanism of lens protein aggregation. We have been investigating the properties of alpha-crystallin for some time. During the next five years we propose to 1) dertermine the subunit recognition sites in alphaA- and alphaB-crystallins using a synthetic approach where a series of consecutive overlapping peptides encompassing alphaA- and alphaB-crystallins will be tested for recognition sequences, 2) continue the studies to fully characterize the chaperone-sites in both alphaA- and alphaB-crystallins and 3) investigate the role of alpha-crystallin chaperone activity in the aggregation of lens crystallins.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY011981-05
Application #
6518570
Study Section
Visual Sciences A Study Section (VISA)
Program Officer
Liberman, Ellen S
Project Start
1998-02-01
Project End
2005-03-31
Budget Start
2002-04-01
Budget End
2003-03-31
Support Year
5
Fiscal Year
2002
Total Cost
$253,750
Indirect Cost
Name
University of Missouri-Columbia
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
112205955
City
Columbia
State
MO
Country
United States
Zip Code
65211
Santhoshkumar, Puttur; Karmakar, Srabani; Sharma, Krishna K (2016) Structural and functional consequences of chaperone site deletion in ?A-crystallin. Biochim Biophys Acta 1864:1529-38
Raju, Murugesan; Santhoshkumar, Puttur; Sharma, K Krishna (2012) ?A-Crystallin-derived mini-chaperone modulates stability and function of cataract causing ?AG98R-crystallin. PLoS One 7:e44077
Santhoshkumar, Puttur; Raju, Murugesan; Sharma, K Krishna (2011) ?A-crystallin peptide SDRDKFVIFLDVKHF accumulating in aging lens impairs the function of ?-crystallin and induces lens protein aggregation. PLoS One 6:e19291
Raju, Murugesan; Santhoshkumar, Puttur; Henzl, T Michael et al. (2011) Identification and characterization of a copper-binding site in ýýA-crystallin. Free Radic Biol Med 50:1429-36
Raju, Murugesan; Santhoshkumar, Puttur; Sharma, K Krishna (2011) Cataract-causing ?AG98R-crystallin mutant dissociates into monomers having chaperone activity. Mol Vis 17:7-15
Sharma, K Krishna; Santhoshkumar, Puttur (2009) Lens aging: effects of crystallins. Biochim Biophys Acta 1790:1095-108
Santhoshkumar, Puttur; Murugesan, Raju; Sharma, K Krishna (2009) Deletion of (54)FLRAPSWF(61) residues decreases the oligomeric size and enhances the chaperone function of alphaB-crystallin. Biochemistry 48:5066-73
Santhoshkumar, Puttur; Udupa, Padmanabha; Murugesan, Raju et al. (2008) Significance of interactions of low molecular weight crystallin fragments in lens aging and cataract formation. J Biol Chem 283:8477-85
Murugesan, Raju; Santhoshkumar, Puttur; Sharma, K Krishna (2008) Role of alphaBI5 and alphaBT162 residues in subunit interaction during oligomerization of alphaB-crystallin. Mol Vis 14:1835-44
Rao, Guruprasad; Santhoshkumar, Puttur; Sharma, K Krishna (2008) Anti-chaperone betaA3/A1(102-117) peptide interacting sites in human alphaB-crystallin. Mol Vis 14:666-74

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