Intracellular Degradation of Newly Synthesized Collagen

Degradation of newly synthesized collagen.

Explants of rabbit lung parenchyma maintained in serumfree medium incorporate I 14Clproline and I Wllysine into collagen as I “Clhydroxyproline and I Wlhydroxylysine at a constant rate for at least 24 h. Evaluation of the size distribution of the [14Clhydroxyproline and [‘4Clhydroxylysine containing peptides within the explants demonstrated that 20 to 40% of the LY chains of newly synthesized c...

Regulation of the production of secretory proteins: intracellular degradation of newly synthesized "defective" collagen.

Confluent cultures of human fetal lung fibroblasts degrade approximately 10% of their newly synthesized collagen within the cell prior to secretion. This basal level of intracellular degradation could not be inhibited by colchicine or cytochalasin B, inhibitors of microtubular and microfilament function, respectively, or by N(alpha)-p-tosyl-L-lysine chloromethyl ketone, chloroquine, or NH(4)Cl,...

Intracellular Cleavage of Newly Synthesized Low Affinity

Intracellular interaction of collagen-specific stress protein HSP47 with newly synthesized procollagen

Heat shock protein 47 (HSP47), a collagen-specific stress protein, has been postulated to be a collagen-specific molecular chaperone localized in the ER. We previously demonstrated that HSP47 transiently associated with newly synthesized procollagen in the ER (Nakai, A., M. Satoh, K. Hirayoshi, and K. Nagata. 1992. J. Cell Biol. 117:903-914). In the present work, we examined the location where ...

Age-related changes in collagen synthesis and degradation in rat tissues. Importance of degradation of newly synthesized collagen in regulating collagen production.

During developmental growth, collagens are believed to be continuously deposited into an extracellular matrix which is increasingly stabilized by the formation of covalent cross-links throughout life. However, the age-related changes in rates of synthetic and degradative processes are less well understood. In the present study we measured rates of collagen synthesis in vivo using a flooding dos...