TDP-43 enhances translation of specific mRNAs linked to neurodegenerative disease

Nucleic Acids Res. 2019 Jan 10;47(1):341-361. doi: 10.1093/nar/gky972.

Abstract

The RNA-binding protein TDP-43 is heavily implicated in neurodegenerative disease. Numerous patient mutations in TARDBP, the gene encoding TDP-43, combined with data from animal and cell-based models, imply that altered RNA regulation by TDP-43 causes Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. However, underlying mechanisms remain unresolved. Increased cytoplasmic TDP-43 levels in diseased neurons suggest a possible role in this cellular compartment. Here, we examined the impact on translation of overexpressing human TDP-43 and the TDP-43A315T patient mutant protein in motor neuron-like cells and primary cultures of cortical neurons. In motor-neuron like cells, TDP-43 associates with ribosomes without significantly affecting global translation. However, ribosome profiling and additional assays revealed enhanced translation and direct binding of Camta1, Mig12, and Dennd4a mRNAs. Overexpressing either wild-type TDP-43 or TDP-43A315T stimulated translation of Camta1 and Mig12 mRNAs via their 5'UTRs and increased CAMTA1 and MIG12 protein levels. In contrast, translational enhancement of Dennd4a mRNA required a specific 3'UTR region and was specifically observed with the TDP-43A315T patient mutant allele. Our data reveal that TDP-43 can function as an mRNA-specific translational enhancer. Moreover, since CAMTA1 and DENND4A are linked to neurodegeneration, they suggest that this function could contribute to disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyotrophic Lateral Sclerosis / genetics
  • Amyotrophic Lateral Sclerosis / pathology
  • Animals
  • Calcium-Binding Proteins / genetics*
  • Cytoplasm / genetics
  • Cytoplasm / metabolism
  • DNA-Binding Proteins / genetics*
  • Frontotemporal Dementia / genetics
  • Frontotemporal Dementia / pathology
  • Gene Expression Regulation / genetics
  • Humans
  • Mice
  • Microtubule-Associated Proteins / genetics
  • Motor Neurons / metabolism
  • Motor Neurons / pathology
  • Mutation
  • Neurodegenerative Diseases / genetics*
  • Neurodegenerative Diseases / pathology
  • Primary Cell Culture
  • RNA, Messenger / genetics
  • Ribosomes / genetics
  • Trans-Activators / genetics*

Substances

  • CAMTA1 protein, human
  • Calcium-Binding Proteins
  • DENND4A protein, human
  • DNA-Binding Proteins
  • Microtubule-Associated Proteins
  • Mig12 protein, mouse
  • RNA, Messenger
  • TARDBP protein, human
  • Trans-Activators