Manipulation of plasma membrane physical state affects desaturase activity in rat lymphocytes

M. Garcia Zevallos, T. Farkas

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Thymocytes, obtained from young rats, were incubated in the presence of either diheptadecanoylphosphatidylcholine or dioleylphosphatidylcholine vesicles and desaturation of either [1-14C]stearic acid or [1-14C]linoleic acid was followed in the endoplasmic reticulum. Incubation with diheptadecanoylphosphatidylcholine resulted in an accumulation of heptadecanoic acid in the plasma membrane, but not in the endoplasmic reticulum and mitochondria, and an increase in membrane ordering as assessed by diphenylhexatriene fluorescence polarization. A shift to higher temperature of the phase separation in the plasma membrane was also observed. Both Δ9 and Δ6 desaturase activities were enhanced in these cells, with Δ6 responding more intensly. Accumulation of oleic acid in the plasma membrane could not be observed when the cells were incubated in the presence of dioleylphosphatidylcholine vesicles, but all the membranes separated, including the microsomes, became more fluid. This can be attributed to removal of cholesterol by the vesicles. Fluidization of plasma membrane and endoplasmic reticulum depressed the conversion of stearate to oleate and linoleate to γ-linolenate. It is concluded that there is an exchange of information between the plasma membrane and the endoplasmic reticulum in order to maintain the proper fluidity relationships and that this occurs without transfer of lipids from the former to the latter.

Original languageEnglish
Pages (from-to)546-552
Number of pages7
JournalArchives of Biochemistry and Biophysics
Volume271
Issue number2
DOIs
Publication statusPublished - 1989

Fingerprint

Lymphocytes
Cell membranes
Rats
Endoplasmic Reticulum
Cell Membrane
Linoleic Acid
Oleic Acid
Diphenylhexatriene
Membranes
Stearates
Mitochondria
Fluorescence Polarization
alpha-Linolenic Acid
Fluidity
Fluidization
Thymocytes
Microsomes
Phase separation
Fluorescence
Cholesterol

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Manipulation of plasma membrane physical state affects desaturase activity in rat lymphocytes. / Zevallos, M. Garcia; Farkas, T.

In: Archives of Biochemistry and Biophysics, Vol. 271, No. 2, 1989, p. 546-552.

Research output: Contribution to journalArticle

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