Abstract:
Regulation of the complement activation (RCA) has been shown to play a key role in controlling activation of the complement
cascades as the main part of innate immune system. Humans RCAs have been studied most extensively and classified into
soluble and membrane type. RCAs have also been partly characterized in a limited variety of non-mammalians species,
including in bony fish, such as carp and zebrafish. In recent year, we have found three isoforms of complement regulatory
membrane proteins (Tecrem) in ginbuna crucian carp at mRNA level, namely gTecrem-1, gTecrem-2, and gTecrem-3 in which
structurally homologous to mammalian RCA-membrane type (CD46). In this study, phylogenetic analyses and comparative
study on gTecrem structure were performed to clarify fundamental molecular information. Data based on mRNA level indicated
that gTecrem structure principally conserved all the features of non-mammalians and human membrane-bound RCA. In
addition, the findings showed that the number of Short Concensus Repeat (SCRs) in regulatory membrane-bound protein is
different across isoforms and animal spesies.
