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Molecular cloning of a mouse 47âkDa heatâshock protein (HSP47), a collagenâbinding stress protein, and its expression during the differentiation of F9 teratocarcinoma cells
- TAKECHI, Hajime, HIRAYOSHI, Kazunori, NAKAI, Akira, KUDO, Hitoshi, SAGA, Shinsuke, NAGATA, Kazuhiro
- European journal of biochemistry 1992 v.206 no.2 pp. 323-329
- cDNA libraries, chicks, collagen, complementary DNA, endoplasmic reticulum, gene expression, heat, heat shock proteins, humans, messenger RNA, mice, molecular cloning, precipitin tests, proteinase inhibitors, retinoic acid, serine proteinases, signal peptide, two-dimensional gel electrophoresis
- A 47âkDa heatâshock protein (HSP47) is a major collagenâbinding stress protein residing in the endoplasmic reticulum, and is assumed to be a molecular chaperone specific to collagen. Twoâdimensional gel electrophoresis and immunoprecipitation studies showed that the expression of HSP47 was significantly induced during the differentiation of mouse teratocarcinoma F9 cells by treatment with retinoic acid alone or with retinoic acid and dibutyryladenosine 3â²,5â²âphosphate. The induction of typeâIV collagen was also observed during F9âcell differentiation. For further analysis, we cloned cDNA encoding mouse HSP47 from a cDNA library of BALB/c 3T3 cells and performed Northernâblot analysis. The cDNA contained a signal sequence at the Nâterminus and an endoplasmicâreticulumâretention signal, RDEL, at the Câterminus. An homology search revealed that mouse HSP47, as well as chick HSP47, belonged to the serine protease inhibitor superfamily. While chick HSP47 mRNA was 4.5 kb with a long (2âkb) 3â² untranslated region, mouse and human HSP47 mRNA were 2.5 kb, with a 0.8âkb 3â² untranslated region. Northernâblot analysis revealed that the concurrent induction of HSP47 and typeâIV collagen during F9âcell differentiation, and the transient induction of HSP47 after heat shock was regulated at the level of mRNA accumulation. These results suggested that HSP47 was closely related to collagens in terms of its expression as well as in its functional relevance.