Kevin Clark

Professional History:

2002-present, Research Scientist, Laboratory of Michael R. Strand, Department of Entomology, University of Georgia, Athens, GA

2000-2001, Associate Scientist, Laboratory of Michael R. Strand, Department of Entomology, University of Wisconsin-Madison .

1998-2000, Assistant Scientist, Laboratory of Michael R. Strand, Department of Entomology, University of Wisconsin-Madison .

1994-1998, Postdoctoral Fellow, Laboratory of Michael R. Strand, Department of Entomology, University of Wisconsin-Madison .

1991-1994, Postdoctoral Fellow, Laboratory of David L. Nelson, Department of Biochemistry, University of Wisconsin-Madison .

1984-1991 Graduate Research Assistant, Department of Biochemistry, University of Wisconsin-Madison. Pharmacology of the GTP Purinergic Receptor from Paramecium tetraurelia. Advisor: Dr. David L. Nelson

Research interests:

Discovery and Characterization of the Insect Cytokine Plasmatocyte Spreading Peptide (PSP)

The focus of my research is to understand the biochemistry of cellular immunity in the insect, Pseudoplusia includens, (Lepidoptera:Noctuidae). Insects possess immune systems that are capable of recognizing and killing entities as diverse as bacteria, fungi, and parasitoid eggs. To deal with this diversity, insects have devised two basic mechanisms for defending themselves:

A hemocyte (blood cell based) method that is used primarily to attack macroinvaers such as egg-laying parasitoid wasps


hemocytes react by spreading and sticking to surfaces

A humoral (non-cellular based) method that is the primary means of eliminating micro-invaders such as bacteria and fungi.

The humoral components of insect blood include a diverse and interesting array of many well-characterized anti-bacterial and anti- fungal peptides. However, my primary interest is to determine how hemocytes are capable of recognizing, attacking, and killing targets such as parasitoid eggs and larvae. This is a complex process that requires a specific and well-coordinated response by the hemocytes.

Publications:

Mark R. Brown, Kevin D. Clark, Monica Gulia, Zhangwu Zhao, Stephen F. Garczynski, Joe W. Crim, Richard J. Suderman, and Michael R. Strand. 2008. An insulin-like peptide regulates egg maturation and metabolism in the mosquito Aedes aegypti. PNAS. 105: 5716-5721.

Gerd Gäde, Heather G. Marco, Petr Simek, Neil Audsley, Kevin D. Clark and Robert J. Weaver. 2008. Predicted versus expressed adipokietic hormones, and other small peptides from the corpus cardiacum-corpus allatum: A case study with beetles and moths. Peptides. 29: 1124-1139.

Gade, G., Simek, P., Clark, K. D., and L. Auerswald. 2006. Unique translational modification of an invertebrate neuropeptide: a phosphorylated member of the adipokinetic hormone peptide family. Biochem. J., 393: 705-713.

Strand, M. R., M. H. Beck, M. D. Lavine, and K. D. Clark. 2006. Microplitis demolitor bracovirus inhibits phagocytosis by hemocytes from Pseudoplusia includens. Arch Insect Biochem. Physiol., 61: 134-145.

Strand, M. R., M. H. Beck, M. D. Lavine, and K. D. Clark. 2005. Microplitis demolitor bracovirus inhibits phagocytosis by hemocytes from Pseudoplusia includens. Arch Insect Bich. Physiol. In press.

Clark, K. D., Y. Kim, M. R. Strand. 2005. Plasmatocyte sensitivity to plasmatocyte spreading peptide (PSP) fluctuates with the larval molting cycle. J. Insect Physiol. 51, 587-596.

Yoshida, M., T. Aizawa, T. Nakamura, K. Shitara, Y. Hayakawa, K. Matsubara, K. Miura, T. Kouno, K. D. Clark, M. R. Strand, M. Mizuguchi, M. Demura, K. Nitta and K. Kawano. 2004. The Gly-Gly Linker Region of the Insect Cytokine Growth Blocking Peptide (GBP) is Essential for Activity. J. Biol. Chem. 279, 51331-51337.
Clark, K. D., Garczynski, S., Arora, A., Crim, J. and M.R. Strand. 2004. Specific residues in plasmatocyte spreading peptide are required for receptor binding and functional antagonism of insect immune cells. J. Biol. Chem. 279: 33246-33252.

Clark, K. D., B. F. Volkman, B. F., H. Thoetiatikal, H., B. King, Y. Hayakawa and M. R. Strand. 2001. Alanine-scanning mutagenesis of plasmatocyte spreading peptide identifies critical residues for biological activity. J. Biol. Chem. 276: 18491-18496.

Strand, M. R., Y. Hayakawa, and K. C. Clark. 2000. Plasmatocyte spreading peptide (PSP1) and growth blocking peptide (GBP) are multifunctional homologs. J. Insect Physiol. 46: 817-824.

Strand, M. R. and K. C. Clark. 1999. Plasmatocyte spreading peptide induces spreading of plasmatocytes but represses spreading of granulocytes. Arch. Insect Biochem. Physiol. 42: 213-223.

Strand, M. R., K. C. Clark and E. M. M. Gardiner. 1999. Plasmatocyte spreading peptide does not induce Microplitis demolitor polydnavirus-infected plasmatocytes to spread on foreign surfaces. Arch. Insect Bich. Physiol. 42: 213-223.

Volkman, B. J., M. E. Anderson, K. D. Clark, Y. Hayakawa, M. R. Strand and J. L. Markley. 1999. Structure of the insect cytokine Plasmatocyte Spreading Peptide from Pseudoplusia includens. J. Biol. Chem. 274: 4493-4496.

Clark, K. D., A. Witherell and M. R. Strand. 1998. Plasmatocyte spreading peptide is encoded by an mRNA differentially expressed in tissues of the moth Pseudoplusia includens. Biochem. Biophys. Res. Comm. 250: 479-485.

Clark, K., L. L. Pech and M. R. Strand. 1997. Isolation and identification of a plasmatocyte spreading peptide from hemolymph of the lepidopteran insect Pseudoplusia includens. J. Biol. Chem. 272: 23440-2344.