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ZFIN ID: ZDB-PUB-200110-6
ESCRT subunit CHMP4B localizes to primary cilia and is required for the structural integrity of the ciliary membrane
Jung, E., Choi, T.I., Lee, J.E., Kim, C.H., Kim, J.
Date: 2020
Source: FASEB journal : official publication of the Federation of American Societies for Experimental Biology   34: 1331-1344 (Journal)
Registered Authors: Kim, Cheol-Hee
Keywords: ciliopathy phenotype, endosomal sorting complex, membrane curvature
MeSH Terms:
  • Animals
  • Cell Membrane/genetics
  • Cell Membrane/metabolism*
  • Cilia/genetics
  • Cilia/metabolism*
  • Endosomal Sorting Complexes Required for Transport/genetics
  • Endosomal Sorting Complexes Required for Transport/metabolism*
  • Gene Deletion
  • Humans
  • Mice
  • NIH 3T3 Cells
  • Zebrafish/genetics
  • Zebrafish/metabolism*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 31914703 Full text @ FASEB J.
Proteins specialized in the detection, generation, or stabilization of membrane curvature play important roles in establishing various morphologies of cells and cellular organelles. Primary cilia are cellular organelles that protrude from the cell surface using a microtubule-based cytoskeleton called the axoneme as a structural support. It is unclear whether the integrity of the high curvature of the ciliary membrane depends on membrane curvature-related proteins. Charged Multivesicular Body Protein 4B (CHMP4B), a subunit of the endosomal sorting complexes required for transport (ESCRT), can stabilize membrane curvature. Here we show that CHMP4B is involved in the assembly and maintenance of primary cilia. CHMP4B was localized to primary cilia in mammalian cells. Knockdown of CHMP4B interfered with cilium assembly and also caused fragmentation of preexisting cilia. By contrast, cilium formation was unaffected by the interruption of the ESCRT-dependent endocytic degradation pathway. Morpholino (MO)-mediated CHMP4B depletion in zebrafish embryos induced characteristic phenotypes of ciliary defects such as curved body axis, hydrocephalus, otolith malformation, and kidney cyst. Our study reveals a new role for the multifunctional protein CHMP4B as a key factor in maintaining the structural integrity of primary cilia.