| First Author | Kasper D | Year | 1996 |
| Journal | J Cell Biol | Volume | 134 |
| Issue | 3 | Pages | 615-23 |
| PubMed ID | 8707842 | Mgi Jnum | J:34571 |
| Mgi Id | MGI:82026 | Doi | 10.1083/jcb.134.3.615 |
| Citation | Kasper D, et al. (1996) Neither type of mannose 6-phosphate receptor is sufficient for targeting of lysosomal enzymes along intracellular routes. J Cell Biol 134(3):615-23 |
| abstractText | Mouse embryonic fibroblasts that are deficient in the two mannose 6-phosphate receptors (MPRs) MPR 46 and MPR 300 missort the majority (> or = 85%) of soluble lysosomal proteins into the medium. Human MPR 46 and MPR 300 were expressed in these cells to test whether overexpression of a single type of MPR can restore transport of lysosomal proteins to lysosomes. Only a partial correction of the missorting was observed after overexpression of MPR 46. Even at MPR 46 levels that are five times higher than the wild-type level, more than one third of the newly synthesized lysosomal proteins accumulates in the secretions. Two-fold overexpression of MPR 300 completely corrects the missorting of lysosomal enzymes. However, at least one fourth of the lysosomal enzymes are transported along a secretion-recapture pathway that is sensitive to mannose 6-phosphate in medium. In control fibroblasts that express both types of MPR, the secretion-recapture pathway is of minor importance. These results imply that neither overexpression of MPR 46 nor MPR 300 is sufficient for targeting of lysosomal proteins along intracellular routes. |
