Molecular cloning of murine p68, a Ca‐binding protein of the lipocortin family

A plasmid cDNA library prepared from a T‐lymphocyte clone of murine strain B10.A origin was screened by cross‐species DNA hybridisation using a partial human p68 cDNA clone, identified as containing coding sequences for previously determined amino‐acid sequences. The longest p68 cDNA insert from this library and a full‐length cDNA insert from a second similar library were fully sequenced. A comparison of the derived amino‐acid sequence with that of human p68 revealed extensive homology (95% overall). Homology at the nucleotide level was 89% in the open reading frame and 85% and 50% in the 5′ (33 nucleotides) and 3′ (347 nucleotides) non‐coding regions respectively. Eight segments of internal homology were observed, each containing a highly conserved consensus region of 17 amino acids correlating with that described for several membrane associated calcium‐binding proteins [Geisow, M. J., Fritsche, U., Hexham, J. M. & Johnson, T. (1986) Nature (Lond.) 320, 636–638]. These results provide further evidence that p68 is a member of the same gene family as p32, p36 and lipocortin I and demonstrate an unusually high level of inter‐species sequence conservation of p68 between mouse and human. Copyright © 1988, Wiley Blackwell. All rights reserved