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Identification and characterization of troponin genes in Locusta migratoria
Author(s) -
Liang H.F.,
Li J.,
Li X.D.
Publication year - 2020
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1111/imb.12644
Subject(s) - gene isoform , biology , troponin complex , troponin c , alternative splicing , gene , biochemistry , ef hand , intron , tropomyosin , troponin , myosin , microbiology and biotechnology , peptide sequence , myocardial infarction , psychology , psychiatry
Troponin complex comprises three subunits, namely troponin C (TpnC), troponin I (TpnI) and troponin T (TpnT), and regulates the contraction of striated muscle. We found that the locust Locusta migratoria genome has one TpnT gene ( LmTpnT ), one TpnI gene ( LmTpnI ) and three TpnC genes ( LmTpnC1 , LmTpn C2 and LmTpn C3 ). Through alternative splicing, LmTpnT and LmTpnI potentially encode two and eight isoforms, respectively. The flight muscle and the jump muscle of L . migratoria express an identical LmTpnT isoform, but different LmTpnC isoforms and LmTpnI isoforms. LmTpnC2 and LmTpnC3 both contain highly conserved residues essential for calcium binding in the EF‐hand II and IV, thus belonging two‐site isoform. LmTpnC1 contains non‐conserved substitutions in the EF‐hand II and all highly conserved residues for calcium binding in the EF‐hand IV. Mutagenesis and tyrosine fluorescence spectroscopic analysis show that both the EF‐hand II and IV of LmTpnC1 can serve as calcium‐binding site. Therefore, all three LmTpnC isoforms belong to two‐site isoform. This is in contrast to the situation in the insect with asynchronous flight muscle, which expresses both one‐site isoform and two‐site isoform of TpnC. Those results suggest that the origination of insect asynchronous flight muscle is associated with the emergence of one‐site isoform of TpnC.