Intracellular degradation of newly synthesized secretory proteins

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,...

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...

Intracellular Cleavage of Newly Synthesized Low Affinity

Phasic release of newly synthesized secretory proteins in the unstimulated rat exocrine pancreas

Pancreatic lobules from fasted rats secrete pulse-labeled proteins in two phases comprising 15 and 85% of basal output, respectively. The first (0-6.5 h) is initially (less than or equal to 0.5 h) unstimulated by secretagogues, probably represents vesicular traffic of Golgi and post-Golgi origin (including condensing vaculoles/immature granules), and notably contains two groups of polypeptides ...

Getting Newly Synthesized Proteins into Shape

Universitä t Freiburg with the analysis of folding of specific endogenous proteins in mutant strains, these studies have led to signifi-Hermann Herder Str. 7 D-79104 Freiburg cant advances in our understanding of protein folding in the complex cellular milieu. Germany Nascent chains emerging at the peptide exit tunnel of Madison, Wisconsin 53706 the ribosome are awaited by a welcoming committee...