Open AccessIsolation and Characterization of Goldfish Y Box Protein, a Germ‐cell‐specific RNA‐binding Protein
Author(s) -
Katsu Yoshinao,
Yamashita Masakane,
Nagahama Yoshitaka
Publication year - 1997
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1997.00854.x
Subject(s) - microbiology and biotechnology , biology , blot , binding protein , cyclin a , messenger rna , complementary dna , cyclin b , recombinant dna , cyclin b1 , cyclin , biochemistry , cell cycle , cell , gene , cyclin dependent kinase 1
Cyclin B is a regulatory subunit of maturation‐promoting factor. In goldfish ( Carassius auratus ) oocytes, cyclin B is synthesized de novo after stimulation by 17α,20β‐dihydroxy‐4‐pregnen‐3‐one (maturation‐inducing hormone). In this study, we examined goldfish oocyte proteins bound to cyclin B mRNA. Using oligo(dT)‐cellulose affinity chromatography and northwestern blotting analysis, we identified a 54‐kDa cyclin B mRNA‐binding protein (p54). Southwestern blotting analysis showed the binding of p54 to the Y box DNA element (CTGATTGGCCAA), suggesting that p54 is a Y box protein in goldfish. We isolated two cDNA clones, GFYP1 and GFYP2, the latter of which encodes a germell‐specific Y box protein. An antibody against a GFYP2 protein recognized p54, suggesting that p54 is identical or highly similar to GFYP2 protein. This is also supported by the finding that a recombinant GFYP2 expressed in bacteria bound to both the Y box DNA element and the goldfish cyclin B mRNA synthesized in vitro. These results suggest that p54 is a germ‐cell‐specific Y box protein and is a potential masking protein of cyclin B mRNA in goldfish oocytes.