Analysis of the membrane proteome of canine pancreatic rough microsomes identifies a novel Hsp40, termed ERj7.
The rough ER (rER) plays a central role in the biogenesis of most extracellular and many organellar proteins in eukaryotic cells. Cells that are specialized in protein secretion, such as pancreatic cells, are particularly rich in rER. In the process of cell homogenization, the rER is converted into ribosome-studded vesicles, the so-called rough microsomes. Here we report on a membrane proteomic analysis of canine pancreatic rough microsomes. Special emphasis was placed on components involved in the various aspects of protein biogenesis, such as protein transport, protein folding, protein modification, and protein degradation. Our results indicate that the Hsp70-chaperone network that is present in the pancreatic ER is even more complex than previously thought, and suggest that the pancreatic rER has a significant capacity for protein degradation.
Zahedi
René P
RP
Department of Bioanalytics, Institute for Analytical Sciences (ISAS), Dortmund, Germany.
Völzing
Christian
C
Schmitt
Andreas
A
Frien
Michael
M
Jung
Martin
M
Dudek
Johanna
J
Wortelkamp
Stefanie
S
Sickmann
Albert
A
Zimmermann
Richard
R
D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D002474:Cell-Free System; D004285:Dogs; D018870:Endoplasmic Reticulum, Rough / Q000737:chemistry* / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D013058:Mass Spectrometry; D008861:Microsomes / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010179:Pancreas / Q000737:chemistry* / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000378:metabolism; D016415:Sequence Alignment
D050956:HSP40 Heat-Shock Proteins; D020543:Proteome