Endoplasmic reticulum: a metabolic compartment.
Several biochemical reactions and processes of cell biology are compartmentalized in the endoplasmic reticulum (ER). The view that the ER membrane is basically a scaffold for ER proteins, which is permeable to small molecules, is inconsistent with recent findings. The luminal micro-environment is characteristically different from the cytosol; its protein and glutathione thiols are remarkably more oxidized, and it contains a separate pyridine nucleotide pool. The substrate specificity and activity of certain luminal enzymes are dependent on selective transport of possible substrates and co-factors from the cytosol. Abundant biochemical, pharmacological, clinical and genetic data indicate that the barrier function of the lipid bilayer and specific transport activities in the membrane make the ER a separate metabolic compartment.
Department of Medical Chemistry, Semmelweis University and Endoplasmic Reticulum Research Group of the Hungarian Academy of Sciences, 1444 Budapest, Hungary.
Miklós
M
Csala
Gábor
G
Bánhegyi
Angelo
A
Benedetti
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D003600:Cytosol / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*
D008565:Membrane Proteins