Loss of the zymogen granule protein syncollin affects pancreatic protein synthesis and transport but not secretion.
Syncollin is a small protein that is abundantly expressed in pancreatic acinar cells and that is tightly associated with the lumenal side of the zymogen granule membrane. To shed light on the hitherto unknown function of syncollin, we have generated syncollin-deficient mice. The mice are viable and show a normal pancreatic morphology as well as normal release kinetics in response to secretagogue stimulation. Although syncollin is highly enriched in zymogen granules, no change was found in the overall protein content and in the levels of chymotrypsin, trypsin, and amylase. However, syncollin-deficient mice reacted to caerulein hyperstimulation with a more severe pancreatitis. Furthermore, the rates of both protein synthesis and intracellular transport of secretory proteins were reduced. We conclude that syncollin plays a role in maturation and/or concentration of zymogens in zymogen granules.
Antonin
Wolfram
W
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry 37077 Göttingen, Germany.
Wagner
Martin
M
Riedel
Dietmar
D
Brose
Nils
N
Jahn
Reinhard
R
D000595:Amino Acid Sequence; D000681:Amylases / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification; D004721:Endoplasmic Reticulum / Q000737:chemistry; D015698:Genomic Library; D006579:Heterozygote; D006720:Homozygote; D008565:Membrane Proteins / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D008817:Mice, Mutant Strains; D018832:Molecular Chaperones / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010179:Pancreas / Q000502:physiology* / Q000648:ultrastructure; D014176:Protein Biosynthesis; D021381:Protein Transport; D022142:Secretory Vesicles / Q000502:physiology* / Q000648:ultrastructure; D014404:Tubulin / Q000302:isolation & purification
D002352:Carrier Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; C107454:Sycn protein, rat; D014404:Tubulin; D000681:Amylases