| Deubiquitination is an important regulatory step in the Ub-dependent pathway.Deubiquitinases are cystering proteases that specifically remove Ub from substrate proteins,which are the largest family of enzymes in Ub-dependent pathway.DUBs are involved in lots of regulatory mechanisms including growth and oncogenesis,differentiation,development,chromosome structure and transcriptional regulation,memory and neurodegenerative diseases.The ubiquitination enzyme Ubp8 in yeast plays important role in regulating cell processes,such as affecting the chromatin structure through the SAGA complex,and ubiquitining Snfl kinase.The Snfl pathway is highly conserved in the fungus which is involved in carbon metabolism inhibition.It was reported that Snfl played an important role in pathogenicity of Magnaporthe oryzae.The homologous gene of Ubp8 in M.oryzae is MGG03527 which is named as Moubpl.Bioinformatics analysis found that Moubp1 has conserved zinc finger structure and the UCH domain.Through functional analysis of Moubpl knockout mutant,we found that the conidiophore and conidia formation of Moubpl knockout mutant was reduced,and the mutant produced more abnormal conidia with lessseptum than wild type strain.And the defect phenotypes also included the delay of germination and appressorium formation.Besides,we also found the dramatic decrease of pathogenicity of mutant through inoculating on onion epidermis,barley and rice leaves.Meanwhile,compared to wide type,we found that the relative expression of melanin related genes reduced in the mutant strain.And the mutant was sensitive to hydrogen peroxide and SDS.The observation of Moubpl-GFP suggested that the subcellular localization of Moubpl was in cytoplasm.We also found that comparing to wild type,the Moubpl mutant grow slower on xylose medium and is less sensitive to 2 deoxy D glucose.Above all,we suggest that Moubp1 play an important role in pathogenecity and involve in carbon metabolism of M.oryzae. |
PDF Full Text Request