Purification and characterisation of cathepsin B mRNA 3'-untranslated-region-binding protein (CBBP), a protein that represses cathepsin B mRNA translation.
We reported that the 3'-untranslated region (3'-UTR) of cathepsin B mRNA of Sarcophaga peregrina (flesh fly) is necessary for the repression of its translation, and detected the 3'-UTR-binding protein in lysates of larval hemocytes in which cathepsin B mRNA translation was repressed [Yano, T., Kurata, S. & Natori, S. (1995) Eur. J. Biochem. 234, 39-43]. In this study, we purified the 3'-UTR-binding protein from an embryonic cell line of Sarcophaga. The purified protein (CBBP) was found to repress cathepsin B mRNA translation in a rabbit reticulocyte lysate. We found that the CBBP contents of the hemocytes did not change during metamorphosis, although the cathepsin B mRNA became translatable only at the pupal stage. Moreover, we found that pupal, but not larval hemocytes, contained a factor that inhibited the binding of CBBP to the 3'-UTR. A regulatory mechanism of cathepsin B expression in Sarcophaga hemocytes is discussed.
Yano
T
T
Faculty of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Japan.
Kobayashi
A
A
Kurata
S
S
Natori
S
S
D000818:Animals; D002401:Cathepsin B / Q000235:genetics*; D002460:Cell Line; D004175:Diptera; D006434:Hemocytes / Q000737:chemistry; D007814:Larva / Q000737:chemistry; D008675:Metamorphosis, Biological; D008970:Molecular Weight; D014176:Protein Biosynthesis / Q000187:drug effects; D011679:Pupa / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D011817:Rabbits
D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D002401:Cathepsin B