| First Author | Ishida Y | Year | 2006 |
| Journal | Mol Biol Cell | Volume | 17 |
| Issue | 5 | Pages | 2346-55 |
| PubMed ID | 16525016 | Mgi Jnum | J:112523 |
| Mgi Id | MGI:3656447 | Doi | 10.1091/mbc.E05-11-1065 |
| Citation | Ishida Y, et al. (2006) Type I collagen in Hsp47-null cells is aggregated in endoplasmic reticulum and deficient in N-propeptide processing and fibrillogenesis. Mol Biol Cell 17(5):2346-55 |
| abstractText | Heat-shock protein of 47 kDa (Hsp47) is a molecular chaperone that recognizes collagen triple helices in the endoplasmic reticulum (ER). Hsp47-knockout mouse embryos are deficient in the maturation of collagen types I and IV, and collagen triple helices formed in the absence of Hsp47 show increased susceptibility to protease digestion. We show here that the fibrils of type I collagen produced by Hsp47-/- cells are abnormally thin and frequently branched. Type I collagen was highly accumulated in the ER of Hsp47-/- cells, and its secretion rate was much slower than that of Hsp47+/+ cells, leading to accumulation of the insoluble aggregate of type I collagen within the cells. Transient expression of Hsp47 in the Hsp47-/- cells restored normal extracellular fibril formation and intracellular localization of type I collagen. Intriguingly, type I collagen with unprocessed N-terminal propeptide (N-propeptide) was secreted from Hsp47-/- cells and accumulated in the extracellular matrix. These results indicate that Hsp47 is required for correct folding and prevention of aggregation of type I collagen in the ER and that this function is indispensable for efficient secretion, processing, and fibril formation of collagen. |
