tailieunhanh - báo cáo khoa học: " Novel induced mlo mutant alleles in combination with site-directed mutagenesis reveal functionally important domains in the heptahelical barley Mlo protein"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Novel induced mlo mutant alleles in combination with site-directed mutagenesis reveal functionally important domains in the heptahelical barley Mlo protein | Reinstădler et al. BMC Plant Biology 2010 10 31 http 1471-2229 10 31 BMC Plant Biology RESEARCH ARTICLE Open Access Novel induced mlo mutant alleles in combination with site-directed mutagenesis reveal functionally important domains in the heptahelical barley Mlo protein Anja Reinstadler 1 Judith Muller1 2 Jerzy H Czembor3 Pietro Piffanelli4 5 Ralph Panstruga1 Abstract Background Recessively inherited natural and induced mutations in the barley Mlo gene confer durable broadspectrum resistance against the powdery mildew pathogen Blumeria graminis . hordei. Mlo codes for a member of a plant-specific family of polytopic integral membrane proteins with unknown biochemical activity. Resistant barley mlo mutant alleles identify amino acid residues that are critical for Mlo function in the context of powdery mildew susceptibility. Results We molecularly analyzed a novel set of induced barley mlo mutants and used site-directed mutagenesis in combination with transient gene expression to unravel novel amino acid residues of functional significance. We integrate these results with previous findings to map functionally important regions of the heptahelical Mlo protein. Our data reveal the second and third cytoplasmic loop as being particularly sensitive to functional impediment by mutational perturbation suggesting that these regions are critical for the susceptibility-conferring activity of the Mlo protein. In contrast only mutations in the second but not the third cytoplasmic loop appear to trigger the Endoplasmic Reticulum-localized quality control machinery that ensures the biogenesis of properly folded membrane proteins. Conclusion Our findings identify functionally important regions of the polytopic barley Mlo protein and reveal the differential sensitivity of individual protein domains to cellular quality control. Background The powdery mildew disease caused by obligate bio-trophic ascomycete fungi of the order Erysiphales is a major .