Small heat-shock proteins regulate membrane lipid polymorphism

Nelly M. Tsvetkova, Ibolya Horváth, Zsolt Török, Willem F. Wolkers, Zsolt Balogi, Natalia Shigapova, Lois M. Crowe, Fern Tablin, Elizabeth Vierling, John H. Crowe, László Vígh

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Abstract

Thermal stress in living cells produces multiple changes that ultimately affect membrane structure and function. We report that two members of the family of small heat-shock proteins (sHsp) (α-crystallin and Synechocystis HSP17) have stabilizing effects on model membranes formed of synthetic and cyanobacterial lipids. In anionic membranes of dimyristoylphosphatidylglycerol and dimyristoylphosphatidylserine, both HSP17 and α-crystallin strongly stabilize the liquid-crystalline state. Evidence from infrared spectroscopy indicates that lipid/sHsp interactions are mediated by the polar headgroup region and that the proteins strongly affect the hydrophobic core. In membranes composed of the nonbilayer lipid dielaidoylphosphatidylethanolamine, both HSP17 and α-crystallin inhibit the formation of inverted hexagonal structure and stabilize the bilayer liquid-crystalline state, suggesting that sHsps can modulate membrane lipid polymorphism. In membranes composed of monogalactosyldiacylglycerol and phosphatidylglycerol (both enriched with unsaturated fatty acids) isolated from Synechocystis thylakoids, HSP17 and α-crystallin increase the molecular order in the fluid-like state. The data show that the nature of sHsp/membrane interactions depends on the lipid composition and extent of lipid unsaturation, and that sHsps can regulate membrane fluidity. We infer from these results that the association between sHsps and membranes may constitute a general mechanism that preserves membrane integrity during thermal fluctuations.

Original languageEnglish (US)
Pages (from-to)13504-13509
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume99
Issue number21
DOIs
StatePublished - Oct 15 2002

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ASJC Scopus subject areas

  • Genetics
  • General

Cite this

Tsvetkova, N. M., Horváth, I., Török, Z., Wolkers, W. F., Balogi, Z., Shigapova, N., Crowe, L. M., Tablin, F., Vierling, E., Crowe, J. H., & Vígh, L. (2002). Small heat-shock proteins regulate membrane lipid polymorphism. Proceedings of the National Academy of Sciences of the United States of America, 99(21), 13504-13509. https://doi.org/10.1073/pnas.192468399