2 TCP-1-RELATED BUT HIGHLY DIVERGENT GENE FAMILIES EXIST IN OAT ENCODING PROTEINS OF ASSUMED CHAPERONE FUNCTION

Tcp-1-related sequences have been isolated from a cDNA library of etio lated 6-day-old oat (Avena sativa) seedlings. This attempt was made to obtain cDNAs of a recently published 60 kDa plant chaperone that re-f olds denatured phytochrome and which was biochemically characterised a s a Tcp-1-related protein [(1993) Nature 363, 644--647]. The translati on of the putative coding sequence from one full-length cDNA clone dis plays no specific homologies to amino acid sequences known from peptid e sequencing of the oat 60 kDa chaperone. Antibodies raised against th e 60 kDa chaperone and over-expressed protein from one full-length cod ing sequence for Tcp-1 from oat show no cross-reactivity, whereas a mo noclonal antibody raised against mouse Tcp-1 protein recognizes both t he 60 kDa protein purified from plant extracts and over-expressed prot ein from Tcp-1-related cDNA sequences.