Person:
Wang, Songyu

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Wang

First Name

Songyu

Name

Wang, Songyu
Author's Publications: search.filters.isAuthorOfPublication.33382039-3c89-4aae-bb7f-cddec043db08

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Multiple mechanisms determine ER network morphology during the cell cycle in Xenopus egg extracts
    (The Rockefeller University Press, 2013) Wang, Songyu; Romano, Fabian B.; Field, Christine; Mitchison, Tim J.; Rapoport, Tom
    In metazoans the endoplasmic reticulum (ER) changes during the cell cycle, with the nuclear envelope (NE) disassembling and reassembling during mitosis and the peripheral ER undergoing extensive remodeling. Here we address how ER morphology is generated during the cell cycle using crude and fractionated Xenopus laevis egg extracts. We show that in interphase the ER is concentrated at the microtubule (MT)-organizing center by dynein and is spread by outward extension of ER tubules through their association with plus ends of growing MTs. Fusion of membranes into an ER network is dependent on the guanosine triphosphatase atlastin (ATL). NE assembly requires fusion by both ATL and ER-soluble N-ethyl-maleimide–sensitive factor adaptor protein receptors. In mitotic extracts, the ER converts into a network of sheets connected by ER tubules and loses most of its interactions with MTs. Together, these results indicate that fusion of ER membranes by ATL and interaction of ER with growing MT ends and dynein cooperate to generate distinct ER morphologies during the cell cycle.
  • Thumbnail Image
    Publication
    Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network
    (eLife Sciences Publications, Ltd, 2016) Wang, Songyu; Tukachinsky, Hanna; Romano, Fabian B; Rapoport, Tom
    In higher eukaryotes, the endoplasmic reticulum (ER) contains a network of membrane tubules, which transitions into sheets during mitosis. Network formation involves curvature-stabilizing proteins, including the reticulons (Rtns), as well as the membrane-fusing GTPase atlastin (ATL) and the lunapark protein (Lnp). Here, we have analyzed how these proteins cooperate. ATL is needed to not only form, but also maintain, the ER network. Maintenance requires a balance between ATL and Rtn, as too little ATL activity or too high Rtn4a concentrations cause ER fragmentation. Lnp only affects the abundance of three-way junctions and tubules. We suggest a model in which ATL-mediated fusion counteracts the instability of free tubule ends. ATL tethers and fuses tubules stabilized by the Rtns, and transiently sits in newly formed three-way junctions. Lnp subsequently moves into the junctional sheets and forms oligomers. Lnp is inactivated by mitotic phosphorylation, which contributes to the tubule-to-sheet conversion of the ER. DOI: http://dx.doi.org/10.7554/eLife.18605.001