糙皮侧耳蛋白质N-糖基化修饰对高温胁迫的响应及其功能OA

[Objective]Investigating the response of protein N-glycosylation modifications in Pleurotus ostreatus to high temperature stress and elucidating its functional role in the resistance of P.ostreatus high temperature stress.[Method]The content of total protein and mannose-glycosylated protein in whole cells and cell walls of P.ostreatus under high temperature stress(42℃)were analyzed,together with the levels of sugar donors and intermediate metabolites involved in protein N-glycosylation,as well as the expression of key genes in the protein N-glycosylation pathway.Additionally,the content changes of total protein and mannoproteins in whole cells and cell walls of P.ostreatus after treatment with tunicamycin(an N-glycosylation inhibitor)were examined,with hygromycin(a polypeptide syn-thesis inhibitor)used as a control.The recovery of mycelial growth after sequential treatment with hygromycin or tunicamycin followed by 24 h of high-temperature stress was compared.[Result]Under prolonged exposure to high temperature stress(42℃),P.ostreatus mycelium exhibited a progressive increase in total protein content,while showing steady declines in whole-cell mannose-glycosylated proteins,total cell wall proteins,and cell wall-associated mannose-glycosylated proteins.Following 24 h of high temperature stress,the contents of glycosylation sugar donors GDP-mannose,UDP-N-acetylglucosamine,and dolichyl diphosphate were 36.90,5.20,3.50-fold higher than those of the control,respectively.Conversely,the content of the protein N-glycosylation intermediates metabolites dolichyl-phosphate and β-1,4-D-mannosylchitobiosyldiphospho-dolichol were decreased markedly to 0.23 and 0.06-fold of the control.Concurrently,the expression levels of key N-glycosylation-related genes(alg1,alg7,alg13,and alg14)was downregulated to 0.13,0.59,0.28 and 0.07-fold of the baseline levels.Notably,tunicamycin treatment significantly reduced the contents of total cellular mannoproteins,cell wall total protein,and cell wall mannoproteins in P.ostreatus.Following high temperature stress,tunicamycin-treated mycelia demonstrated enhanced recovery growth rate com-pared to untreated controls,whereas the opposite trend was observed under hygromycin treatment.[Conclusion]P.ostreatus enhances its resistance to high temperature stress by reducing N-glycosylation levels of proteins.