PUBLICATION

Functional importance of NUDT9H domain and N-terminal ADPR-binding pocket in two species variants of vertebrate TRPM2 channels

Authors
Kühn, F.J.P., Ehrlich, W., Barth, D., Kühn, C., Lückhoff, A.
ID
ZDB-PUB-191218-5
Date
2019
Source
Scientific Reports   9: 19224 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Adenosine Diphosphate Ribose/genetics
  • Adenosine Diphosphate Ribose/metabolism*
  • HEK293 Cells
  • Cell Line
  • TRPM Cation Channels/genetics
  • TRPM Cation Channels/metabolism*
  • Amino Acid Sequence
  • Vertebrates/genetics
  • Vertebrates/metabolism*
  • Point Mutation/genetics
  • Zebrafish/genetics
  • Zebrafish/metabolism
  • Protein Binding/physiology*
  • Humans
  • Binding Sites/physiology*
  • Animals
  • Sea Anemones/genetics
  • Sea Anemones/metabolism
PubMed
31844070 Full text @ Sci. Rep.
Abstract
There are at least two different principles of how ADP-ribose (ADPR) induces activation of TRPM2 channels. In human TRPM2, gating requires the C-terminal NUDT9H domain as ADPR-binding module, whereas in sea anemone, NUDT9H is dispensable and binding of ADPR occurs N-terminally. Zebrafish TRPM2 needs both, the N-terminal ADPR-binding pocket and NUDT9H. Our aim was to pinpoint the relative functional contributions of NUDT9H and the N-terminal ADPR-binding pocket in zebrafish TRPM2, to identify fundamental mechanisms of ADPR-directed gating. We show that the NUDT9H domains of human and zebrafish TRPM2 are interchangeable since chimeras generate ADPR-sensitive channels. A point mutation at a highly conserved position within NUDT9H induces loss-of-function in both vertebrate channels. The substrate specificity of zebrafish TRPM2 corresponds to that of sea anemone TRPM2, indicating gating by the proposed N-terminal ADPR-binding pocket. However, a point mutation in this region abolishes ADPR activation also in human TRPM2. These findings provide functional evidence for an uniform N-terminal ADPR-binding pocket in TRPM2 of zebrafish and sea anemone with modified function in human TRPM2. The structural importance of NUDT9H in vertebrate TRPM2 can be associated with a single amino acid residue which is not directly involved in the binding of ADPR.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping