User:Andor J Kiss: Difference between revisions
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# '''Adaptive and evolutionary physiology of vertebrate animals.''' More specifically I am interested in their adaptation to extreme cold and heat, and how their physiological systems have evolved to allow them to exploit such niches. The model system that I have been using is that of the proteins in the eye lens. The proteins are called “crystallins” and play an important role in light refraction. Most vertebrates (excluding some birds) have three kinds of crystallins; alpha (α), beta (β) and gamma (γ). Alpha crystallin is also a type of small heat shock (sHSP) protein and comes in at least two flavours (isoforms). One of these α isoforms can be found widely expressed outside the eye lens and has important roles as a stress protein in a number of tissues. The β and γ crystallins are part of the same super-gene family, but presently there are no known non-refractive structure/function roles. Adaptation of ectothermic vertebrate lenses to cold is of interest to me as means of modeling not only lens cataracts, but to modeling globular protein stability. Cold-cataracts in mammalian lens have been used to model senile cataracts. Many ectothermic vertebrates that are cold-adapted do not show a cold-cataract. Thus, the appearance or absence of a lens cataract is a rare example of a protein model system that allows investigation into stability of globular non-enzymatic proteins. | # '''Adaptive and evolutionary physiology of vertebrate animals.''' More specifically I am interested in their adaptation to extreme cold and heat, and how their physiological systems have evolved to allow them to exploit such niches. The model system that I have been using is that of the proteins in the eye lens. The proteins are called “crystallins” and play an important role in light refraction. Most vertebrates (excluding some birds) have three kinds of crystallins; alpha (α), beta (β) and gamma (γ). Alpha crystallin is also a type of small heat shock (sHSP) protein and comes in at least two flavours (isoforms). One of these α isoforms can be found widely expressed outside the eye lens and has important roles as a stress protein in a number of tissues. The β and γ crystallins are part of the same super-gene family, but presently there are no known non-refractive structure/function roles. Adaptation of ectothermic vertebrate lenses to cold is of interest to me as means of modeling not only lens cataracts, but to modeling globular protein stability. Cold-cataracts in mammalian lens have been used to model senile cataracts. Many ectothermic vertebrates that are cold-adapted do not show a cold-cataract. Thus, the appearance or absence of a lens cataract is a rare example of a protein model system that allows investigation into stability of globular non-enzymatic proteins. | ||
#'''Structure/Function of | #'''Structure/Function basis of long-term stability of globular protein systems.''' A second major interest of mine is molecular (amino acid) adaptations that occur in globular (structural) proteins which impart a long-term stability. Lenses from ectothermic animals are ideal systems to study this problem as these animals (including their lenses) are thermally adapted to their native environments (whether cold or hot). Human lenses do not show thermal adaptation thus providing an excellent comparative basis to determine the structural basis of the instability in many mammalian lenses. In fact, human lenses exhibit a so-called “cold-cataract” at temperatures below +20°C, which has been used to model not only senile (age-related) cataracts, but also other protein condensation diseases such as Alzheimer's Diseases and Sickle Cell Anæmia. The common thread through each of these pathologies are instabilities in the globular/structural proteins. By using a novel cross-species chaperone assay developed in my lab (Kiss ''et. al.'', 2004) , coupled with phylogenetic analysis (Kiss ''et. al.'', 2008), and mass-spectrometry proteomics approaches, we are identifying individual crystallins and their residue changes and their post-translational modifications that we believe have increased the stability of the crystallins and thus maintaining lens transparency. | ||
Revision as of 07:53, 1 January 2009
Contact Info
- Visiting Assistant Professor
- Department of Zoology
- 194 Pearson Hall
- Miami University
- Oxford, OH 45056
I work in collaboration with the Laboratory for Ecophysiological Cryobiology and am a member of the Center for Visual Sciences at Miami University.
Education
- 2005, PhD, University of Illinois at Urbana-Champaign (Animal Biology)
- 1999, MSc, University of Western Ontario (Molecular Genetics/Zoology)
- 1994, BSc, University of Victoria (Biochemistry & Microbiology)
Research interests
- Adaptive and evolutionary physiology of vertebrate animals. More specifically I am interested in their adaptation to extreme cold and heat, and how their physiological systems have evolved to allow them to exploit such niches. The model system that I have been using is that of the proteins in the eye lens. The proteins are called “crystallins” and play an important role in light refraction. Most vertebrates (excluding some birds) have three kinds of crystallins; alpha (α), beta (β) and gamma (γ). Alpha crystallin is also a type of small heat shock (sHSP) protein and comes in at least two flavours (isoforms). One of these α isoforms can be found widely expressed outside the eye lens and has important roles as a stress protein in a number of tissues. The β and γ crystallins are part of the same super-gene family, but presently there are no known non-refractive structure/function roles. Adaptation of ectothermic vertebrate lenses to cold is of interest to me as means of modeling not only lens cataracts, but to modeling globular protein stability. Cold-cataracts in mammalian lens have been used to model senile cataracts. Many ectothermic vertebrates that are cold-adapted do not show a cold-cataract. Thus, the appearance or absence of a lens cataract is a rare example of a protein model system that allows investigation into stability of globular non-enzymatic proteins.
- Structure/Function basis of long-term stability of globular protein systems. A second major interest of mine is molecular (amino acid) adaptations that occur in globular (structural) proteins which impart a long-term stability. Lenses from ectothermic animals are ideal systems to study this problem as these animals (including their lenses) are thermally adapted to their native environments (whether cold or hot). Human lenses do not show thermal adaptation thus providing an excellent comparative basis to determine the structural basis of the instability in many mammalian lenses. In fact, human lenses exhibit a so-called “cold-cataract” at temperatures below +20°C, which has been used to model not only senile (age-related) cataracts, but also other protein condensation diseases such as Alzheimer's Diseases and Sickle Cell Anæmia. The common thread through each of these pathologies are instabilities in the globular/structural proteins. By using a novel cross-species chaperone assay developed in my lab (Kiss et. al., 2004) , coupled with phylogenetic analysis (Kiss et. al., 2008), and mass-spectrometry proteomics approaches, we are identifying individual crystallins and their residue changes and their post-translational modifications that we believe have increased the stability of the crystallins and thus maintaining lens transparency.
Publications
-
Kiss,A.J. and Cheng,C-H.C. (2008). Molecular diversity and genomic organisation of the α, β and γ eye lens crystallins from the Antarctic toothfish Dissostichus mawsoni doi:10.1016/j.cbd.2008.02.002
- Kiss AJ, Mirarefi AY, Ramakrishnan S, Zukoski CF, Devries AL, and Cheng CH. Cold-stable eye lens crystallins of the Antarctic nototheniid toothfish Dissostichus mawsoni Norman. J Exp Biol. 2004 Dec;207(Pt 26):4633-49. DOI:10.1242/jeb.01312 |
Above article highlighted as an editorial feature Blindingly Cold in the ‘Inside JEB’ section of Journal of Experimental Biology.
- Kiss A, Farah K, Kim J, Garriock RJ, Drysdale TA, and Hammond JR. Molecular cloning and functional characterization of inhibitor-sensitive (mENT1) and inhibitor-resistant (mENT2) equilibrative nucleoside transporters from mouse brain. Biochem J. 2000 Dec 1;352 Pt 2(Pt 2):363-72.
- Hunt JG, Kasinsky HE, Elsey RM, Wright CL, Rice P, Bell JE, Sharp DJ, Kiss AJ, Hunt DF, Arnott DP, Russ MM, Shabanowitz J, and Ausió J. Protamines of reptiles. J Biol Chem. 1996 Sep 20;271(38):23547-57. DOI:10.1074/jbc.271.38.23547 |
- ISBN:9780123741691
Chapter Contribution: The Antarctic Toothfish: A new model system for eye lens biology.
