Nuclear localization of the zebrafish tight junction protein nagie oko.
The tight junctions-associated MAGUK protein nagie oko is closely related to Drosophila Stardust, mouse protein associated with lin-seven 1 (Pals1), and human MAGUK p55 subfamily member 5 (Mpp5). As a component of the evolutionarily conserved Crumbs protein complex, nagie oko is essential for the maintenance of epithelial cell polarity. Here, we show that nagie oko contains a predicted nuclear export and two conserved nuclear localization signals. We find that loss of the predicted nuclear export signal results in nuclear protein accumulation. We show that nagie oko nuclear import is redundantly controlled by the two nuclear localization signals and the evolutionarily conserved region 1 (ECR1), which links nagie oko with Par6-aPKC. Finally, deletion forms of nagie oko that lack nuclear import and export signals complement several nagie oko mutant defects in cell polarity and epithelial integrity. This finding provides an entry point to potentially novel and unknown roles of this important cell polarity regulator.
Max Delbrück Center (MDC) for Molecular Medicine, Berlin, Germany.
Nana
N
Bit-Avragim
Stefan
S
Rohr
Franziska
F
Rudolph
Peter
P
Van der Ven
Dieter
D
Fürst
Jenny
J
Eichhorst
Burkhard
B
Wiesner
Salim
S
Abdelilah-Seyfried
D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism*; D016764:Cell Polarity / Q000235:genetics; D019295:Computational Biology; D004847:Epithelial Cells / Q000378:metabolism; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D051571:Protein Kinase C-alpha / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
D029961:Zebrafish Proteins; D051571:Protein Kinase C-alpha; C501511:mpp5a protein, zebrafish; D006162:Guanylate Cyclase