Evolution and Expression of Paxillin Genes in Teleost Fish.
BACKGROUND
Paxillin family proteins regulate intracellular signaling downstream of extracellular matrix adhesion. Tissue expression patterns and cellular functions of Paxillin proteins during embryo development remain poorly understood. Additionally, the evolution of this gene family has not been thoroughly investigated.


RESULTS
This report characterizes the evolution and expression of a novel Paxillin gene, called Paxillin-b, in Teleosts. Alignments indicate that Teleost Paxillin-a and Paxillin-b proteins are highly homologous to each other and to human Paxillin. Phylogenetic and synteny analyses suggest that these genes originated from the duplication of an ancestral Paxillin gene that was in a common ancestor of Teleosts and Tetrapods. Analysis of the spatiotemporal expression profiles of Paxillin-a and Paxillin-b using zebrafish revealed both overlapping and distinct domains for Paxillin-a and Paxillin-b during embryo development. Localization of zebrafish Paxillin orthologs expressed in mammalian cells demonstrated that both proteins localize to focal adhesions, similar to mammalian Paxillin. This suggests these proteins regulate adhesion-dependent processes in their endogenous tissues.


CONCLUSIONS
Paxillin-a and Paxillin-b were generated by duplication in Teleosts. These genes likely play similar roles as Paxillin genes in other organisms. This work provides a framework for functional investigation of Paxillin family members during development using the zebrafish as an in vivo model system.
Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, Syracuse, New York, 13210, United States of America.
Andrew E
AE
Jacob
Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, Syracuse, New York, 13210, United States of America.
Christopher E
CE
Turner
Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, Syracuse, New York, 13210, United States of America.
Jeffrey D
JD
Amack
D000818:Animals; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005399:Fishes / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D022001:Focal Adhesions / Q000378:metabolism*; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051419:Paxillin / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D026801:Synteny; D015027:Zebrafish / Q000196:embryology / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics
D029941:Fish Proteins; C496061:PXN protein, human; D051419:Paxillin; D029961:Zebrafish Proteins; C496064:pxna protein, zebrafish