IDENTIFICATION OF PLANT CYTOSKELETAL, CELL CYCLE-RELATED AND POLARITY-RELATED PROTEINS USING SCHIZOSACCHAROMYCES-POMBE

The fission yeast Schizosaccharomyces pombe has been used to identify Arabidopsis thaliana proteins that may play a role in cell shape maint enance or cell cycle regulation. An Arabidopsis thaliana cDNA library was constructed in pREP5N vector under the control of the inducible nm t1 promoter and transformed into S. pombe. Expression of the A. thalia na sequences was induced and clones showing severe morphological chang es were identified and analysed. Comparison of the sequences of the in serts with the sequence data bases revealed that several cDNAs encode proteins known to play a role in function of the cytoskeleton, the cel l cycle and establishment of cell polarity. These include alpha-1, alp ha-2, alpha-6 and beta-6 tubulins, myosin heavy chain-like protein, ub iquitin conjugating enzymes UBC9 (E2), 26S protease subunits, Ran-bind ing protein, myb protein, PRL1 gene product and rho protein. Approxima tely 30% of the clones encode novel sequences. The results suggest tha t S. pombe phenotypic screening can be used to identify plant proteins involved in cell shape maintenance and regulation during cell cycle a nd development.