REEP3 and REEP4 determine the tubular morphology of the endoplasmic reticulum during mitosis

Darshan Kumar, Banafsheh Golchoubian, Ilya Belevich, Eija Jokitalo, Anne-Lore Schlaitz

Research output: Contribution to journalArticleScientificpeer-review


The endoplasmic reticulum (ER) is extensively remodeled during metazoan open mitosis. However, whether the ER becomes more tubular or more cisternal during mitosis is controversial, and dedicated factors governing the morphology of the mitotic ER have remained elusive. Here, we describe the ER membrane proteins REEP3 and REEP4 as major determinants of ER morphology in metaphase cells. REEP3/4 are specifically required for generating the high-curvature morphology of mitotic ER and promote ER tubulation through their reticulon homology domains (RHDs). This ER-shaping activity of REEP3/4 is distinct from their previously described function to clear ER from metaphase chromatin. We further show that related REEP proteins do not contribute to mitotic ER shaping and provide evidence that the REEP3/4 carboxyterminus mediates regulation of the proteins. These findings confirm that ER converts to higher curvature during mitosis, identify REEP3/4 as specific and crucial morphogenic factors mediating ER tubulation during mitosis, and define the first cell cycle-specific role for RHD proteins.
Original languageEnglish
JournalMolecular Biology of the Cell
Issue number12
Pages (from-to)1377-1389
Publication statusPublished - 1 Jun 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1182 Biochemistry, cell and molecular biology

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