The CHD Protein, Kismet, is Important for the Recycling of Synaptic Vesicles during Endocytosis

Sci Rep. 2019 Dec 18;9(1):19368. doi: 10.1038/s41598-019-55900-6.

Abstract

Chromatin remodeling proteins of the chromodomain DNA-binding protein family, CHD7 and CHD8, mediate early neurodevelopmental events including neural migration and differentiation. As such, mutations in either protein can lead to neurodevelopmental disorders. How chromatin remodeling proteins influence the activity of mature synapses, however, is relatively unexplored. A critical feature of mature neurons is well-regulated endocytosis, which is vital for synaptic function to recycle membrane and synaptic proteins enabling the continued release of synaptic vesicles. Here we show that Kismet, the Drosophila homolog of CHD7 and CHD8, regulates endocytosis. Kismet positively influenced transcript levels and bound to dap160 and endophilin B transcription start sites and promoters in whole nervous systems and influenced the synaptic localization of Dynamin/Shibire. In addition, kismet mutants exhibit reduced VGLUT, a synaptic vesicle marker, at stimulated but not resting synapses and reduced levels of synaptic Rab11. Endocytosis is restored at kismet mutant synapses by pharmacologically inhibiting the function of histone deacetyltransferases (HDACs). These data suggest that HDAC activity may oppose Kismet to promote synaptic vesicle endocytosis. A deeper understanding of how CHD proteins regulate the function of mature neurons will help better understand neurodevelopmental disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acyltransferases / genetics
  • Animals
  • Chromatin Assembly and Disassembly / genetics*
  • DNA Helicases / genetics*
  • DNA-Binding Proteins / genetics
  • Drosophila Proteins / genetics*
  • Drosophila melanogaster / genetics
  • Endocytosis / genetics*
  • Histone Deacetylase 1 / genetics
  • Homeodomain Proteins / genetics*
  • Humans
  • Neurons / metabolism
  • Synaptic Vesicles / genetics*
  • Synaptic Vesicles / metabolism
  • Transcription Factors / genetics
  • Transcription Initiation Site / drug effects
  • Vesicular Glutamate Transport Proteins / genetics
  • Vesicular Transport Proteins / genetics
  • rab GTP-Binding Proteins / genetics

Substances

  • CHD8 protein, human
  • DNA-Binding Proteins
  • Dap160 protein, Drosophila
  • Drosophila Proteins
  • Homeodomain Proteins
  • Transcription Factors
  • VGlut protein, Drosophila
  • Vesicular Glutamate Transport Proteins
  • Vesicular Transport Proteins
  • Acyltransferases
  • endophilin B, Drosophila
  • HDAC1 protein, Drosophila
  • Histone Deacetylase 1
  • Rab11 protein, Drosophila
  • DNA Helicases
  • CHD7 protein, human
  • rab GTP-Binding Proteins
  • kis protein, Drosophila