Cell-type control of membrane biogenesis induced by HMG-CoA reductase.
Quantitative increases in HMG-CoA reductase, the rate-limiting enzyme in sterol biosynthesis, induce membrane biogenesis in both yeast and mammalian cells. The subcellular organization of the resulting membrane differs in the two cell types: mammalian cells generate crystalloid endoplasmic reticulum whereas yeast cells assemble karmellae. We examined the consequences of heterologous expression of HMG-CoA reductase to distinguish features of this response that were cell-type specific from those that were isozyme-specific. This analysis demonstrated that membrane proliferation was induced in both mammalian and yeast cells by HMG-CoA reductase from either organism. However, the morphology of the induced membranes was determined by the cell type rather than the particular isozyme. Thus, both yeast and mammalian HMG-CoA reductase contained functional signals for membrane proliferation that were operational in either cell type, but the qualitative response to those signals was cell-type specific.
Wright
R
R
University of California, Department of Molecular and Cellular Biology, Berkeley, CA 94720.
Keller
G
G
Gould
S J
SJ
Subramani
S
S
Rine
J
J
D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D006224:Cricetinae; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000502:physiology*; D007425:Intracellular Membranes / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000502:physiology*; D008322:Mammals / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008647:Mesocricetus / Q000235:genetics; D009928:Organ Specificity; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D006903:Hydroxymethylglutaryl CoA Reductases