Alternative relay regulates the adenosine triphosphatase activity of Locusta migratoria striated muscle myosin  

作　　者：Jie Hao Chang Liu Ning Zhang Jing Li Tong Ni Mingbo Qu Xiang-dong Li 

机构地区：[1]State Key Laboratory oflntegrated Management of lnsect Pests and Rodents,Insttute of Zoology,Chinese Academy of Sciences,Bejing,China [2]University of Chinese Academy of Sciences,Bejing,China [3]School of Bioengeering,Dalian University of Technology,Dalian,China

出　　处：《Insect Science》2024年第2期435-447,共13页昆虫科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(31672359 and 31970657);State Key Laboratory of Integrated Management of Pest Insects and Rodents(Grant No.IPM1601).

摘　　要：Locust(Locusta migratoria)has a single striated muscle myosin heavy chain(Mhc)gene,which contains 5 clusters of alternative exclusive exons and 1 differently included penultimate exon.The alternative exons of Mhc gene encode 4 distinct regions in the myosin motor domain,that is,the N-terminal SH3-like domain,one lip of the nucleotide-binding pocket,the relay,and the converter.Here,we investigated the role of the alternative regions on the motor function of locust muscle myosin.Using Sf9-baculovirus protein expression system,we expressed and purified 5 isoforms of the locust muscle myosin heavy meromyosin(HMM),including the major isoform in the thorax dorsal longitudinal flight muscle(FL1)and 4 isoforms expressed in the abdominal intersegmental muscle(AB1 to AB4).Among these 5 HMMs,FL1-HMM displayed the highest level of actin-activated adenosine triphosphatase(ATPase)activity(hereafter referred as ATPase activity).To identify the alternative region(s)responsible for the elevated ATPase activity of FL1-HMM,we produced a number of chimeras of FL1-HMM and AB4-HMM.Substitution with the relay of AB4-HMM(encoded by exon-14c)substantially decreased the ATPase activity of FL1-HMM,and conversely,the relay of FL1-HMM(encoded by exon-14a)enhanced the ATPase activity of AB4-HMM.Mutagenesis showed that the exon-14a-encoded residues Gly474 and Asn509 are responsible for the elevated ATPase activity of FL1-HMM.Those results indicate that the alternative relay encoded by exon-14a/c play a key role in regulating the ATPase activity of FL1-HMM and AB4-HMM.

关 键 词：alternative splicing ATPASE Locusta migratoria molecular motor MUSCLE MYOSIN 

分 类 号：Q96[生物学—昆虫学]