Lipid species affect morphology of endoplasmic reticulum: a sea urchin oocyte model of reversible manipulation

The ER is a large multifunctional organelle of eukaryotic cells. Malfunction of the ER in various disease states, such as atherosclerosis, diabetes, cancer, Alzheimer's and Parkinson's and amyotrophic lateral sclerosis, often correlates with alterations in its morphology. The ER exhibits r...

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Detalhes bibliográficos
Autores: Ulloa, Gabriela, Hamati, Fadi, Dick, Alexander, Fitzgerald, Julie, Mantell, Judith, Verkade, Paul, Collinson, Lucy M., Arkill, Kenton, Larijani, Banafshé, Poccia, Dominic
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/404412
Acesso em linha:http://hdl.handle.net/10261/404412
https://api.elsevier.com/content/abstract/scopus_id/85074444865
Access Level:acceso abierto
Palavra-chave:Confocal microscopy
Diacylglycerol
Electron tomography
Lipid kinases
Membrane lipids
Negative spontaneous curvature
Phospholipases
Serial blockface scanning electron microscopy
Descrição
Resumo:The ER is a large multifunctional organelle of eukaryotic cells. Malfunction of the ER in various disease states, such as atherosclerosis, diabetes, cancer, Alzheimer's and Parkinson's and amyotrophic lateral sclerosis, often correlates with alterations in its morphology. The ER exhibits regionally variable membrane morphology that includes, at the extremes, large relatively flat surfaces and interconnected tubular structures highly curved in cross-section. ER morphology is controlled by shaping proteins that associate with membrane lipids. To investigate the role of these lipids, we developed a sea urchin oocyte model, a relatively quiescent cell in which the ER consists mostly of tubules. We altered levels of endogenous diacylglycerol (DAG), phosphatidylethanolamine (PtdEth), and phosphatidylcholine by microinjection of enzymes or lipid delivery by liposomes and evaluated shape changes with 2D and 3D confocal imaging and 3D electron microscopy. Decreases and increases in the levels of lipids such as DAG or PtdEth characterized by negative spontaneous curvature correlated with conversion to sheet structures or tubules, respectively. The effects of endogenous alterations of DAG were reversible upon exogenous delivery of lipids of negative spontaneous curvature. These data suggest that proteins require threshold amounts of such lipids and that localized deficiencies of the lipids could contribute to alterations of ER morphology. The oocyte modeling system should be beneficial to studies directed at understanding requirements of lipid species in interactions leading to alterations of organelle shaping.