title: The plant cytoskeleton, NET3C, and VAP27 mediate the link between the plasma membrane and endoplasmic reticulum.
abstract: The cortical endoplasmic reticulum (ER) network in plants is a highly dynamic structure, and it contacts the plasma membrane (PM) at ER-PM anchor/contact sites. These sites are known to be essential for communication between the ER and PM for lipid transport, calcium influx, and ER morphology in mammalian and fungal cells. The nature of these contact sites is unknown in plants, and here, we have identified a complex that forms this bridge. This complex includes (1) NET3C, which belongs to a plant-specific superfamily (NET) of actin-binding proteins, (2) VAP27, a plant homolog of the yeast Scs2 ER-PM contact site protein, and (3) the actin and microtubule networks. We demonstrate that NET3C and VAP27 localize to puncta at the PM and that NET3C and VAP27 form homodimers/oligomers and together form complexes with actin and microtubules. We show that F-actin modulates the turnover of NET3C at these puncta and microtubules regulate the exchange of VAP27 at the same sites. Based on these data, we propose a model for the structure of the plant ER-PM contact sites.
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK.
authors.forename: Pengwei
authors.initials: P
authors.lastname: Wang
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Hawkins
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK.
authors.forename: Christine
authors.initials: C
authors.lastname: Richardson
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Cummins
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Deeks
authors.affiliation: Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP, UK.
authors.forename: Imogen
authors.initials: I
authors.lastname: Sparkes
authors.affiliation: Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Hawes
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK. Electronic address: p.j.hussey@durham.ac.uk.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Hussey
mesh_terms: D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D050683:R-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; C000601165:At3g60600 protein, Arabidopsis; D008565:Membrane Proteins; D008840:Microfilament Proteins; C000601164:NET3C protein, Arabidopsis; D050683:R-SNARE Proteins