pI(Cln) and cytosolic F-actin constitute a heteromeric complex with a constant molecular mass in rat skeletal muscles.
To elucidate the function of pI(Cln), its localization in subcellular organellae was investigated. A specific polyclonal anti-pI(Cln) antibody detected the soluble 38-kDa pI(Cln) exclusively in the cytosols of rat heart, lung, liver, spleen, skeletal muscle, testis, and brain, but not rat kidney. pI(Cln)-associated proteins in skeletal muscle were also analyzed. Native-gradient PAGE showed a single 340-kDa protein band reactive to anti-pI(Cln) antibody. This band also stained with anti-actin antibody. Two-dimensional PAGE and immunoprecipitation analysis indicated that all of the pI(Cln) was present in association with actin of a constant length: the molecular ratio of pI(Cln) to actin was roughly 1:7. In addition, all actin in the cytosol fractions was found in association with pI(Cln). These results suggest the possibility that skeletal muscle pI(Cln) controls the length of cytosolic F-actin.
Li
Y
Y
Second Department of Biochemistry, Akita University School of Medicine,Akita, 010-8543, Japan.
Tao
G
G
Nagasawa
H
H
Tazawa
H
H
Kobayashi
A
A
Itoh
H
H
Tashima
Y
Y
D000199:Actins / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D018118:Chloride Channels / Q000737:chemistry* / Q000235:genetics; D003600:Cytosol / Q000737:chemistry; D007473:Ion Channels; D046911:Macromolecular Substances; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000737:chemistry; D014018:Tissue Distribution
D000199:Actins; D018118:Chloride Channels; C498729:Clns1a protein, rat; D007473:Ion Channels; D046911:Macromolecular Substances