Tricalbin proteins regulate plasma membrane phospholipid homeostasis

The evolutionarily conserved extended synaptotagmin (E-Syt) proteins are calcium-activated lipid transfer proteins that function at contacts between the ER and plasma membrane (ER-PM contacts). However, roles of the E-Syt family members in PM lipid organisation remain incomplete. Among the E-Syt fam...

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Bibliographic Details
Published inLife science alliance Vol. 5; no. 8; p. e202201430
Main Authors Thomas, Ffion B, Omnus, Deike J, Bader, Jakob M, Chung, Gary Hc, Kono, Nozomu, Stefan, Christopher J
Format Journal Article
LanguageEnglish
Published United States Life Science Alliance LLC 01.08.2022
Subjects
Cell Membrane - metabolism
Homeostasis
Membrane Proteins - genetics
Membrane Proteins - metabolism
Phosphatidylserines - metabolism
Phospholipids - metabolism
Synaptotagmins - metabolism
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Summary:The evolutionarily conserved extended synaptotagmin (E-Syt) proteins are calcium-activated lipid transfer proteins that function at contacts between the ER and plasma membrane (ER-PM contacts). However, roles of the E-Syt family members in PM lipid organisation remain incomplete. Among the E-Syt family, the yeast tricalbin (Tcb) proteins are essential for PM integrity upon heat stress, but it is not known how they contribute to PM maintenance. Using quantitative lipidomics and microscopy, we find that the Tcb proteins regulate phosphatidylserine homeostasis at the PM. Moreover, upon heat-induced membrane stress, Tcb3 co-localises with the PM protein Sfk1 that is implicated in PM phospholipid asymmetry and integrity. The Tcb proteins also control the PM targeting of the known phosphatidylserine effector Pkc1 upon heat-induced stress. Phosphatidylserine has evolutionarily conserved roles in PM organisation, integrity, and repair. We propose that phospholipid regulation is an ancient essential function of E-Syt family members required for PM integrity.
Bibliography:Jakob M Bader’s present address is Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany.
Deike J Omnus’s present address is Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
ISSN:2575-1077
2575-1077
DOI:10.26508/lsa.202201430