Botany & Plant Ecology‪.‬

Analysis of Katnin p60 Homologs in Plants. Rebecca Kelbel and Regina McClinton, Grand Valley State University, Cell and Molecular Biology Program, Allendale, MI 49401 Unlike animal cells, plant cells display a variety of microtubule arrays throughout the cell cycle, yet characterization of the plant microtubule organizing center remains elusive. Katanin is a microtubule severing ATPase, known to localize at the centrosome in animal cells. Katanin has two subunits, one of which, p60, has catalytic activity. An Arabidopisis thaliana homolog of katanin p60 has been identified and sequenced, and named AtKSS (McClinton et al., 2001). Current research aims to analyze the conservation of the katanin p60 throughout the plant kingdom by means of degenerate PCR probing of seedling tissue cDNA. From the AtKSS amino acid sequence, preliminary blasts of 19 angiosperm databases and 2 gymnosperm databases all show identities of y73%. Alignment of these sequences has allowed us to design degenerate primers which we are using to obtain full-length cDNA sequences of p60 homologs. Analysis of sequences shows a high degree of conservation in important regions, mainly the CAD region, which identifies p60 as an AAA protein, and the microtubule binding region. That katanin p60 homologues are present in two plant phyla, in addition to several animal phyla is a strong indication that this protein is conserved throughout the plant kingdom, and perhaps among eukaryotes.