Changes in cell morphology and carnitine acetyltransferase activity in Candida albicans following growth on lipids and serum and after in vivo incubation in mice.
Candida albicans C316, maintained in the yeast form, showed a proliferation of peroxisomes when grown on triolein or serum as sole carbon source but these structures were absent from glucose-grown cells. Peroxisomes were also apparent in C. albicans obtained after injection into mice and recovery from intraperitoneal washings and kidneys; they may therefore be useful markers to assess a potential in vivo response in cells that are growing in vitro. Transcell-wall structures also occurred in C. albicans grown on triolein or serum, and in cells cultured in vivo, but were not seen in cells grown on glucose. These structures consisted of electron-dense fibrillar material penetrating through the cell wall from the plasmalemma side and protruded out to the exterior of the cell. Endoplasmic reticulum, located at the periphery of the cell, was found to be in close proximity with these cell wall structures. Carnitine acetyltransferase (CAT; EC 2.3.1.7), the key enzyme for the translocation of acetyl units between intracellular compartments, was present in low activities in glucose-grown cells; its activity was increased some 100-fold in triolein-grown cells but only 4-fold in serum-grown cells. It was not possible to assess this activity in the in vivo-cultured cells. Two separate CAT proteins, partially purifed from isolated microchondria and peroxisomes, respectively, were identified, with different specificities and kinetic properties.
Sheridan
R
R
Department of Biological Sciences, University of Hull, UK.
Ratledge
C
C
D019342:Acetic Acid / Q000378:metabolism; D000818:Animals; D002176:Candida albicans / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure*; D002332:Carnitine O-Acetyltransferase / Q000378:metabolism*; D002473:Cell Wall / Q000648:ultrastructure; D003470:Culture Media; D005260:Female; D007700:Kinetics; D050356:Lipid Metabolism; D051379:Mice; D008830:Microbodies / Q000648:ultrastructure; D008854:Microscopy, Electron
D003470:Culture Media; D002332:Carnitine O-Acetyltransferase; D019342:Acetic Acid