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Research Interests
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Mitochondria are the powerhouse of the cell. They are believed to be direct descendants of a bacterial endosymbiont that became established at an early stage in a nucleus-containing (but amitochondriate) host cell.
The presence of DNA in mitochondria (mtDNA) was described almost 40 years ago. In humans, mtDNA is about 16,569 bp long and encodes 13 polypeptides, 2rRNA and 22 tRNA genes. The number of polypeptides in the mitochondrial proteome, on the other hand, has been estimated to be as high as 1000. Therefore, most structural proteins and enzymes in mitochondria are encoded by the nuclear genome and are synthesized on cytoplasmic ribosomes. The import of these proteins can occur post-translationally, through the use of mitochondrial targeting sequences (MTS).
It was not until 1988 that mutations in mtDNA were associated with defined human pathologies. According to recent estimates, pathogenic mtDNA defects affect as much as 1 in 15,000 of the adult population. Cells which are highly dependent on oxidative phosphorylation (e.g. neurons, cardiac cells and skeletal muscle cells) are most sensitive to accumulation of mtDNA defects and therefore are most often affected by mitochondrial disease. mtDNA, unlike nuclear DNA, is not protected by histones and, as a consequence, is more susceptible to damage inflicted by different agents, most notably by reactive oxygen species (ROS) generated as a result of electron leakage from the respiratory chain or in response to environmental stress. Accumulation of such damage is believed to be a basis for ageing and acquired mitochondrial diseases. Mutations in mtDNA accumulate as one ages and hence, depending on the environmental stress, an individual can reach a threshold for manifestation of the disease during infancy, adolescence or adulthood.
In any given cell, the fraction of mutant mitochondrial genomes can vary from 0 to 100%. These two extreme conditions are called homoplasmy as opposed to heteroplasmy, when cell has a mixed population of normal and mutant mitochondrial genomes. Factors that lead to the establishment and maintenance of heteroplasmy are currently unknown.
Therefore, I am interested in the biochemical mechanisms used by mitochondria to repair the mtDNA damage and in how deficiencies in these mechanisms lead to pathological changes in the function of cardiac muscle and vascular endothelium, in the cross-talk between nuclear and mitochondrial genomes, in the establishment and maintenance of heteroplasmy and in the developing experimental approaches to manipulate heteroplasmy and mtDNA in general in mammalian cells for the purpose of treatment of mitochondrial desorders.
The second area of my interest is the role of the Eph-Ephrin signaling in the vascular morphogenesis and pathology. Eph receptors, the largest family of receptor tyrosine kinases (RTKs), are unique among RTKs in that they interact with cell-surface bound (as opposed to soluble) ephrin ligands, in that in many cases such interaction induces signaling cascades in both interacting cells (bi-directional signaling) and in that eph signaling does not promote cellular proliferation. The targeted disruption of either EphB4 or its ligand, Ephrin B2, leads to defects in vascular remodeling and is embryonically lethal in mice. Therefore, we believe that signaling through Eph receptors is critically involved in vascular remodeling in various pathologies of pulmonary vasculature.
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EDUCATION |
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| 1992 |
Ph.D. Molecular biology. Institute of Molecular Biology |
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and Genetics, Natl. Acad. Sci. of Ukraine . Kiev , |
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Ukraine |
1982 - 1983 |
Diploma with distinction. Kiev State |
1985 - 1989 |
University (Molecular Biology) |
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RESEARCH POSITIONS |
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11/2001- Present |
Research Assistant Professor. University of |
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South Alabama, Dept. of Pharmacology |
01/1998 - 11/2001 |
Research Assistant Professor. University of |
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South Alabama, Laboratory of Molecular Biology |
09/1996 - 01/1998 |
Research Associate. University of South |
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Alabama, Laboratory of Molecular Biology |
05/1995 - /091996 |
Senior postdoctoral fellow. Texas Heart Institute. |
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Houston, TX |
1993 |
Associate Researcher. Institute of Molecular |
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Biology and Genetics, National Acad. Sci. of |
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Ukraine |
01/1993 - 05/1995 |
LSU Rice Research Station, visiting Assistant |
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Professor |
01/1993 - 07/1993 |
LSU Rice Research Station, visiting scientist |
09/1992 - 01/1993 |
Engineer 1-st category, project leader |
09/1989 - 09/1992 |
Engineer, Institute of Molecular Biology and |
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Genetics, National Acad. Sci. of Ukraine, Kiev |
09/1988 - 04/1989 |
Trainee (Master's student). Department of |
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Genetics, Moscow State University |
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TEACHING |
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09/1991 - 01/1993 |
Lecturer. Regulation of gene expression at |
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pre-translational level. Kiev State University |
1998 - 2001 |
Molecular and Cellular Biology, BEAR program. |
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University of South Alabama |
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PROFESSIONAL SOCIETIES MEMBERSHIP |
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American Association for the Advancement of Science |
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SCIENTIFIC PEER REVIEW |
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Ad hoc reviewer for BioTechniques |
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PUBLICATIONS |
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1. Alexeyev, M.F. and Winkler, H.H. Transposable Dual Reporters for Studying the Structure-Function Relationships in Membrane Proteins: Permissive Sites in R. prowazekii ATP/ADP Translocase Biochemistry 41 (2002) 406-414.
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2. Alexeyev, M.F. and Winkler, H.H. Survey of positively charged residues in Rickettsia prowazekii ATP/ADP translocase. Biochimica et Biophysica Acta. 2002. In press.
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3. Gireesh Rajashekara, Mikhail F. Alexeyev, Shirin Munir, Alberto Back, David A. Halvorson, Kakambi. V. Nagaraja and Carol L. Wells. Pathogenic role of SEF14, SEF17, and SEF21 fimbriae in salmonella enterica serovar enteritidis infection of chickens. Appl Environ Microbiol. 2000 Apr;66(4):1759-63.
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4. Alexeyev, M.F. and Winkler, H.H. Gene synthesis, expression and purification of Rickettsia prowazekii ATP/ADP translocase. Biochim. Biophys. Acta. 1419 (1999) 299-306.
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5. Alexeyev, M.F. The pKNOCK series of broad-host-range mobilizable suicide vectors for gene knockout and targeted DNA insertion into the chromosome of Gram-negative bacteria. BioTechniques 26 (1999) 824-828.
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6. Alexeyev, M.F. and Winkler, H.H. Membrane topology of the Rickettsia prowazekii ATP/ADP translocase revealed by novel dual pho-lac reporters. J. Mol. Biol. 285 (1999) 1503-1513.
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7. Balbas P., Alexeyev M., Shokolenko I. , Bolivar F. and Valle F. A pBRINT family: plasmids for insertion of cloned DNA fragments into the Escherichia coli chromosome. Gene 172 (1996) 65-69.
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8. Alexeyev, M.F., Shokolenko, I.N. and Croughan, T.P. New mini-Tn5 derivatives for insertion mutagenesis and genetic engineering in Gram-negative bacteria. Can. J. Microbiol. 41 (1995) 1053-1055.
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9. Alexeyev, M.F., Shokolenko, I.N. Mini-Tn10 transposon derivatives for insertion mutagenesis and gene delivery in the chromosome of gram-negative bacteria. Gene 160 (1995) 59-62.
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10. Alexeyev, M.F., Shokolenko, I.N. and Croughan, T.P. Improved antibiotic resistance gene cassettes and omega elements for Escherichia coli vector construction and in vitro deletion/insertion mutagenesis. Gene 160 (1995) 63-67.
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11. Alexeyev M.F. and Shokolenko I.N. The RP4 oriT AND RP4 oriT-R6K oriV DNA cassettes for construction of specialized vectors. BioTechniques 19 (1995) 22.
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12. Shokolenko, I.N. and Alexeyev, M.F. Transformation of Klebsiella oxytoca VN13 and Escherichia coli TG1 by freezing-thawing procedure. BioTechniques 18 (1995) 596.
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13. Alexeyev M.F. Three kanamycin resistance gene cassettes with different polylinkers. Bio/Techniques 18 (1995) 52-56.
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14. Kozyrovska, N., Alexeyev, M., Kovtunovich, G., Gun'kovska, N., and Kordium V. Survival of Klebsiella oxytoca VN13 engineered for bioluminescence on barley roots during plant vegetation. Microb. Releases 2 (1994): 261-265.
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15. Kozyrovskaya N.A., Alexeyev M.F., Kovtunovich G.L., Gun’kovskaya N.V., Kordjum V.A. Bioluminiscence-based detection of Klebsiella oxytoca VN13 in the environment. Biopolymery I klitina, 1994 V.10,N2:17-23.
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16. Romanovskaya, V.A., Alexeyev, M.F., Gunkovskaya, N.V., Stolyar, S.M., Shatokhina, E.S., Malashenko Yu.R. Screening for restriction endonucleases in methane oxydising bacteria Ukr. Microbiol. J. 1992 V.54,N6:32-40.
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17. Alexeyev, M.F., Gun'kovskaya, N.V., Romanovskaya, V.A., Malashenko, Yu.R. Methylovarius whittenburyi-producer of Mwh I, the new izoschisomer of HpaI. Ukr. Microbiol. J. 1992 V.54,N6:70‑73.
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18. Alexeyev M.F., Cloning in the lacIq gene of pTTQ plasmids: "reverse" colour reaction. Biopolym.Kletka.1992 V8,N6:58-60.
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19. Nguyen Van Hoa, Alexeyev Mikhail, Kozyrovskaya Natalia, Elhai Jeffrey. Anabaena thermalis: a nitrogen-fixing endorhizosphere cyanobacterium associated with rice. Biopolym. Kletka.1992 V8, N5:44-48.
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20. Alexeyev, M.F., Kovtunovich, G.L., Kravetz, A.N., Solonin, A.S. pZE8 natural hsd plasmid replicon based cloning vectors for Escherichia coli and endorhizosphere nitrogen fixer Klebsiella oxytoca VN13. Biopolym. Kletka.1992 V.8,N5:48‑54.
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21. Alexeyev, M.F. and Gun'kovskaya, N.V. The rapid method for enterobacteria transformation and some factors influencing its efficiency Biopolym. Kletka. 1992 V.8,N3:47-51.
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22. Alexeyev, M.F. and Kozyrovskaya, N.A. Some aspects of molecular cyanobacterial genetics- A review Biopolym. Kletka.1990 V.6,N5:23-45
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PRESENTATIONS |
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1. Liqing Chen, Edward X. Zhou, Brian A. Halloran, Mikhail F. Alexeyev, Nathan N. Aronson, Jr., Edward J. Meehan. Crystal Structure of S. marcescens Chitinase A: Active-Site Mutant W539A. American crystallographic association annual meeting. 2002. Invited abstract W0284
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2. Alexeyev, M.F. and Winkler H.H. Survey of Positively Charged Residues in Rickettsia prowazekii ATP/ADP Translocase. American Society for Microbiology 100th General Meeting. Los Angeles , CA May 21-25, 2000 . Abstract K-43.
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3. Alexeyev, M.F. and Winkler H.H. Dual pho-lac and lac-pho reporters for probing the topology of integral membrane proteins: the Escherichia coli lactose permease (LacY) and Rickettsia prowazekii ATP/ADP translocase (Tlc). American Society for Microbiology 98th General Meeting. Atlanta , GA 1998. Abstract K-90.
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4. Alexeyev, M.F. and Winkler, H.W. Engineering of a synthetic open reading frame with coding capacity for a Rickettsia prowazekii ATP/ADP antiporter protein (translocase). Tirteenth Sesqui-Annual Meeting of the American Society for Rickettsiology. Abstract # 37.
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5. Alexeyev, M.F., Engler, D.A., Scott-burden, T., and Casscells, W. FGF-2 Facilitates uptake of DNA complexes by living cells. ASBMB/ASIP/AAI joint meeting. June 1-6, 1996 . New Orleans , LA. Late Breaking Abstracts LB124.
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6. Croughan, T.P., Cao, H.X., Utomo, H.S., Alexeyev, M.F., Chu, Q.R., Reagan, R.P., Wang, X.H., Meche, M.M., and Trumps, D.B. Application of biotechnology to rice improvement. Proceedings of the 25-th RTWG meeting, New Orleans , LA , March 1994. P. 62.
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7. Romanovskaja, V.A., Alexeyev, M.F., Gun'kovskaya, N.V., Malashenko, Yu.R. Restrictases of metane‑oxidizing bacteria. In Abstracts of FASEB Summer Research Conference Restriction Endonucleases and Modification Methyltransferases: Structure and Mechanisms". Saxstons River, Vermont ( USA ), July 3-8, -1993.-P.96.
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8. Kozyrovskaya, N.A., Alexeyev, M.F., Gun'kovskaya, N.V., Kovtunovich, G.L. and Kordjum, V.A. Monitoring of the nitrogen-fixing bacteria in agroboicenosis. In Abstracts of VIIIth Eastern Europe Symposium on Biological Nitrogen Fixation "Nitrogenfix-92". Saratov ,22-26 Sept.,-1992.-P.39.
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9. Alexeyev, M.F., Kozyrovskaya, N.A., Makitruk, V.L. Klebsiella oxytoca mutants defective in synthesis/excretion of indole compounds. In Abstracts of VIIIth Eastern Europe Symposium on Biological Nitrogen Fixation "Nitrogenfix-92". Saratov , 22-26 Sept., -1992.-P.47.
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10. Romanovskaya, V.A., Gunkovskaya, N.V., Alexeyev, M.F. Restriction endonucleases screening in methane oxydising bacteria. VII Int. Symp. on Microbial Growth on C1 compounds. Warwick . Great Britain 1992, C103.
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11. Alexeyev, M.F., Gun'kovskaya, N.V., Kozyrovskaya, N.A., Makitruk, V.L. and Ruckdashell, E. 1992. Indoles production by plant-associated nitrogen-fixing Klebsiella. In: Abstracts of the 6th International Symposium on Microbial Ecology (ISME-6), Barcelona , 6- 11 September, p.167.
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RESEARCH SUPPORT |
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ONGOING
0255697B Alexeyev M.F. (PI)
7/2002 - 6/2004
American Heart Association Modulation of oxidative mitochondrial DNA damage in the rat cardiac myocytes with cell-permeable enzyme chimeras. |
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