ZFIN ID: ZDB-PUB-100702-3
A Zebrafish (Danio rerio) Endomembrane Antiporter Similar to a Yeast Cation/H+ Transporter is Required for Neural Crest Development
Manohar, M., Mei, H., Franklin, A.J., Sweet, E.M., Shigaki, T., Riley, B.B., Macdiarmid, C.W., and Hirschi, K.D.
Date: 2010
Source: Biochemistry   49(31): 6557-6566 (Journal)
Registered Authors: Riley, Bruce, Sweet, Elly
Keywords: none
MeSH Terms:
  • Animals
  • Antiporters/physiology*
  • Cation Transport Proteins
  • Embryo, Nonmammalian/chemistry
  • Fungal Proteins
  • Hydrogen-Ion Concentration
  • Intracellular Membranes/chemistry
  • Membrane Transport Proteins/physiology
  • Neural Crest/growth & development*
  • Saccharomyces cerevisiae Proteins
  • Sodium-Hydrogen Exchangers
  • Zebrafish*
  • Zebrafish Proteins/physiology*
PubMed: 20578725 Full text @ Biochemistry
CAtion/H+ eXchangers (CAXs) are integral membrane proteins that transport Ca2+ or other cations using the H+ gradient and have been characterized in yeast and plant cells; however, no functional analysis of a vertebrate CAX homolog has yet been reported. In this study, we further characterize a CAX from yeast, VNX1, and initiate characterization of a zebrafish CAX (Cax1). Localization studies indicated that both the Vnx1 and Cax1 are found in endomembrane compartments. Biochemical characterization of endomembrane fractions from vnx1-mutant cells and zebrafish Cax1-expressing yeast cells suggested that both yeast and fish CAXs have Ca2+/H+ antiport activities. Additionally, the vnx1 mutation was associated with heightened pH-sensitivity. In zebrafish embryos, cax1 was specifically expressed in neural crest cells. Morpholino knockdown of cax1 caused defects in neural crest development, including alterations in pigmentation, defects in jaw development, and reduction in expression of the neural crest marker, Pax7. Collectively, our findings provide insights into Vnx1 function and support an unexpected role of CAX transporters in animal growth and development.