NUCLEOTIDE-SEQUENCE OF RAT CALRETININ CDNA

A rat calretinin cDNA clone was selected by antibody screening of a la mbdagt11 brain library. The sequence revealed remarkable nucleotide an d amino acid homology with human calretinin (91.1% and 98.5%, respecti vely), with only four amino acid differences. A high degree of homolog y with chick calretinin was also observed (79.8% and 86.6%, respective ly), with 36 amino acid differences. Although the role of this central nervous system protein has not been well characterized, the evolution arily conserved calcium binding domains and connecting regions, in add ition to the limited local changes observed between rat and chick prim ary structure, lead us to believe that calretinin interacts with other highly conserved constituents of brain cells. This calretinin cDNA cl one provides a new probe for the analysis of a specific subset of neur ons in the central nervous system. The probe will allow a more detaile d analysis of calretinin regulation in the brain and will be useful fo r screening genomic libraries for the complete chromosomal gene.