Increased levels of mitochondrial ATP synthase beta-subunit in fast skeletal muscle of carp acclimated to cold temperature

We compared two-dimensional electrophoretic patterns of cytosolic extracts from fast muscle of the 10 degrees C- and 30 degrees C-acclimated carp Cypr inus carpio, and revealed that cold acclimation resulted in an approximatel y two-fold increase of the expression levels of a 55-kDa protein. This prot ein was identified as mitochondrial ATP synthase beta-subunit by N-terminal amino acid sequencing after electrophoresis along with subsequent cDNA clo ning. A full-length cDNA clone of carp ATP synthase beta-subunit encoded 51 8 amino acids, showing 72-89% identity to those of eukaryotes at the level of amino acid sequence. The accumulated levels of ATP synthase beta-subunit transcripts in the fast muscle from the 10 degrees C- and 30 degrees C-acc limated carp were well correlated with those at the protein level, suggesti ng that expression of this protein during temperature acclimation is regula ted mainly at the transcription level.