Mutations in the microtubule-associated protein MAP11 (C7orf43) cause microcephaly in humans and zebrafish

Brain. 2019 Mar 1;142(3):574-585. doi: 10.1093/brain/awz004.

Abstract

Microtubule associated protein 11 (MAP11, previously termed C7orf43) encodes a highly conserved protein whose function is unknown. Through genome-wide linkage analysis combined with whole exome sequencing, we demonstrate that human autosomal recessive primary microcephaly is caused by a truncating mutation in MAP11. Moreover, homozygous MAP11-orthologue CRISPR/Cas9 knock-out zebrafish presented with microcephaly and decreased neuronal proliferation, recapitulating the human phenotype. We demonstrate that MAP11 is ubiquitously transcribed with high levels in brain and cerebellum. Immunofluorescence and co-immunoprecipitation studies in SH-SY5Y cells showed that MAP11 associates with mitotic spindles, co-localizing and physically associating with α-tubulin during mitosis. MAP11 expression precedes α-tubulin in gap formation of cell abscission at the midbody and is co-localized with PLK1, a key regulator of cytokinesis, at the edges of microtubule extensions of daughter cells post cytokinesis abscission, implicating a role in mitotic spindle dynamics and in regulation of cell abscission during cytokinesis. Finally, lentiviral-mediated silencing of MAP11 diminished SH-SY5Y cell viability, reducing proliferation rather than affecting apoptosis. Thus, MAP11 encodes a microtubule-associated protein that plays a role in spindle dynamics and cell division, in which mutations cause microcephaly in humans and zebrafish.

Keywords: C7orf43; CRISPR/Cas9 zebrafish; MAP11; microcephaly; microtubule-associated protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins / metabolism
  • Child
  • Child, Preschool
  • Cytokinesis
  • Disease Models, Animal
  • Female
  • HeLa Cells
  • Humans
  • Male
  • Microcephaly / etiology*
  • Microcephaly / genetics*
  • Microcephaly / metabolism
  • Microtubule-Associated Proteins / genetics*
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / genetics
  • Mitosis
  • Mutation
  • Polo-Like Kinase 1
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Spindle Apparatus / genetics
  • Tubulin / genetics
  • Tubulin / metabolism
  • Zebrafish / metabolism
  • Zebrafish Proteins / metabolism

Substances

  • Cell Cycle Proteins
  • Microtubule-Associated Proteins
  • Proto-Oncogene Proteins
  • Tubulin
  • Zebrafish Proteins
  • Protein Serine-Threonine Kinases

Supplementary concepts

  • Autosomal Recessive Primary Microcephaly