Cloning and expression of MutS and MutL complexes from Arabidopsis thaliana

GALLES, C.; GÓMEZ, R.; INGA, A.; SPAMPINATO, C.

Pinamar

Congreso; XLI Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2005

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

The mismatch repair (MMR) system is critical for maintaining the overall integrity of the genetic material, and the basic features of this system have been highly conserved during evolution. Proteins unique to the MMR system are known as “Mut” proteins and were originally identified in prokaryotic organisms, where their loss enhances the accumulation of DNA replication errors and results in a mutator phenotype. Plants face unique obstacles to long term genetic integrity. They lack reserved germ lines: gametes arise from meristem cells that have already divided many times. For this reason, plant somatic genome-maintenance activities must be as efficient as eukaryotic counterparts, perhaps more so. The aim of this study was to characterize the proteins involved in the initial step of the plant MMR pathway, MutSa, MutSã and MutLa. MLH1 and PMS1 were obtained by reverse transcription followed by PCR using specific primers. The cDNAs fragments as well as those of MSH2, MSH6 and MSH7 were cloned in compatible expression vectors. It remains to be investigated gene and protein expressions in mitotic (root, meristem), meiotic (flower) and non-mitotic/non-meiotic tissues (leaf). In addition, functional analyses of these A. thaliana protein complexes are being performed in yeast using sensitive yeast reporter systems.