N. Shimokawa et M. Yamaguchi, MOLECULAR-CLONING AND SEQUENCING OF THE CDNA CODING FOR A CALCIUM-BINDING PROTEIN REGUCALCIN FROM RAT-LIVER, FEBS letters, 327(3), 1993, pp. 251-255
The cDNA of a Ca2+-binding protein regucalcin was cloned from a rat li
ver cDNA library which was constructed in lambdaZAPII by immunoscreeni
ng. Positive clones were obtained from which spar ned the region of in
terest, and they gave a sequence of 1.7 kb by sequencing with the dide
oxynucleotide method. Analysis of the sequence of the cloned cDNA show
ed that the cDNA encoded the complete amino acid sequence of the reguc
alcin molecule. Regucalcin was composed of 299 amino acid residues and
its molecular weight was estimated to be 33,388 Da. The hydropathy pr
ofile of regucalcin showed a highly hydrophilic character. The nucleot
ide and amino acid sequences of regucalcin did not have statistically
significant homology, as compared with the registered sequences which
are found in the EMBL and GenBank databases containing several other C
a2+-binding proteins (calmodulin, calbindin-D28k and S-100beta). The r
egucalcin molecule did not contain the EF-hand motif as a Ca2+-binding
domain. The present study demonstrates that regucalcin is a unique Ca
2+-binding protein in the liver of rats.