title: Structural Insights of WHAMM's Interaction with Microtubules by Cryo-EM.
abstract: WASP homolog associated with actin, membranes, and microtubules (WHAMM) is a vertebrate protein functioning in membrane tubulation for intracellular membrane trafficking and specific organelle formation. Composed of multiple domains, WHAMM can bind to membrane and microtubule (MT) and promote actin polymerization nucleation. Previous work revealed that WHAMM's activity to promote actin nucleation is repressed upon binding to MTs. Here, we discovered that WHAMM interacts with αβ-tubulin through a small peptide motif within its MT-binding domain. We reconstructed a high-resolution structure of WHAMM's MT-binding motif (MBM) assembling around MTs using cryo-electron microscopy and verified it with chemical cross-linking and mass spectrometry analysis. We also detected a conformational switch of this motif between the non-MT-bound state and the MT-bound state. These discoveries provide new insights into the mechanism by which WHAMM coordinates actin and MT networks, the two major cytoskeletal systems involved in membrane trafficking and membrane remodeling.
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Tianyang
authors.initials: T
authors.lastname: Liu
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Anbang
authors.initials: A
authors.lastname: Dai
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Meng-Qiu
authors.initials: MQ
authors.lastname: Dong
authors.affiliation: Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China. Electronic address: hongweiwang@tsinghua.edu.cn.
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Wang
mesh_terms: D020285:Cryoelectron Microscopy; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D008870:Microtubules / Q000737:chemistry / Q000648:ultrastructure*; D011485:Protein Binding; D011487:Protein Conformation; D014404:Tubulin / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D014404:Tubulin
keywords: WHAMM; cryo-EM; membrane trafficking; microtubule; microtubule-binding motif