Shifts in the relationship between mRNA and protein abundance of gill ion-transporters during smolt development and seawater acclimation in Atlantic salmon (Salmo salar).

Smolting Atlantic salmon exhibit a seasonal increase in seawater tolerance that is associated with changes in the abundance of major gill ion-transporter transcripts and proteins. In the present study, we investigate how the transcript and protein abundance of specific ion-transporter isoforms relate to each other during smolt development and seawater acclimation, and how each correlates to seawater tolerance. We show that during smolt development both mRNA and protein abundance of gill Na/K-ATPase α1a subunit (NKAα1a) decreased but the decrease in the mRNA was five-times greater than that of the protein.

Differential regulation of sodium-potassium pump isoforms during smolt development and seawater exposure of Atlantic salmon.

Freshwater and seawater isoforms of the alpha subunit of Na(+)/K(+)-ATPase (NKA) have previously been identified in gill ionocytes of Atlantic salmon (Salmo salar). In the present study we examine the abundance and cellular localization of these isoforms during the parr-smolt transformation, a developmental process that is preparatory for seawater entry. The abundance of NKAα1a was lower in smolts than in parr, remained relatively constant during spring and decreased in summer.

Tissue-specific requirements for specific domains in the FERM protein Moe/Epb4.1l5 during early zebrafish development.

Background: The FERM domain containing protein Mosaic Eyes (Moe) interacts with Crumbs proteins, which are important regulators of apical identity and size. In zebrafish, loss-of-function mutations in moe result in defects in brain ventricle formation, retinal pigmented epithelium and neural retinal development, pericardial edema, and tail curvature. In humans and mice, there are two major alternately spliced isoforms of the Moe orthologue, Erythrocyte Protein Band 4.

Mosaic Eyes is a novel component of the Crumbs complex and negatively regulates photoreceptor apical size.

Establishment of apical-basal cell polarity has emerged as an important process during development, and the Crumbs complex is a major component of this process in Drosophila. By comparison, little is known about the role of Crumbs (Crb) proteins in vertebrate development. We show that the FERM protein Mosaic Eyes (Moe) is a novel regulatory component of the Crumbs complex.