PUBLICATION

Analyses of binding partners and functional domains for the developmentally essential protein Hmx3a/HMX3

Authors
Haws, W., England, S., Grieb, G., Susana, G., Hernandez, S., Mirer, H., Lewis, K.
ID
ZDB-PUB-230122-9
Date
2023
Source
Scientific Reports   13: 11511151 (Journal)
Registered Authors
England, Sam, Lewis, Katharine E.
Keywords
none
MeSH Terms
  • Animals
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism
  • Mice
  • Mutation
  • Nerve Tissue Proteins/metabolism
  • Protein Binding
  • Transcription Factors*/metabolism
  • Zebrafish*/metabolism
PubMed
36670152 Full text @ Sci. Rep.
Abstract
HMX3 is a homeodomain protein with essential roles in CNS and ear development. Homeodomains are DNA-binding domains and hence homeodomain-containing proteins are usually assumed to be transcription factors. However, intriguingly, our recent data suggest that zebrafish Hmx3a may not require its homeodomain to function, raising the important question of what molecular interactions mediate its effects. To investigate this, we performed a yeast two-hybrid screen and identified 539 potential binding partners of mouse HMX3. Using co-immunoprecipitation, we tested whether a prioritized subset of these interactions are conserved in zebrafish and found that Tle3b, Azin1b, Prmt2, Hmgb1a, and Hmgn3 bind Hmx3a. Next, we tested whether these proteins bind the products of four distinct hmx3a mutant alleles that all lack the homeodomain. Embryos homozygous for two of these alleles develop abnormally and die, whereas zebrafish homozygous for the other two alleles are viable. We found that all four mutations abrogate binding to Prmt2 and Tle3b, whereas Azin1b binding was preserved in all cases. Interestingly, Hmgb1a and Hmgn3 had more affinity for products of the viable mutant alleles. These data shed light on how HMX3/Hmx3a might function at a molecular level and identify new targets for future study in these vital developmental processes.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping