title: Plakophilin-3 is required for late embryonic amphibian development, exhibiting roles in ectodermal and neural tissues.
abstract: The p120-catenin family has undergone a significant expansion during the evolution of vertebrates, resulting in varied functions that have yet to be discerned or fully characterized. Likewise, members of the plakophilins, a related catenin subfamily, are found throughout the cell with little known about their functions outside the desmosomal plaque. While the plakophilin-3 (Pkp3) knockout mouse resulted in skin defects, we find larger, including lethal effects following its depletion in Xenopus. Pkp3, unlike some other characterized catenins in amphibians, does not have significant maternal deposits of mRNA. However, during embryogenesis, two Pkp3 protein products whose temporal expression is partially complimentary become expressed. Only the smaller of these products is found in adult Xenopus tissues, with an expression pattern exhibiting distinctions as well as overlaps with those observed in mammalian studies. We determined that Xenopus Pkp3 depletion causes a skin fragility phenotype in keeping with the mouse knockout, but more novel, Xenopus tailbud embryos are hyposensitive to touch even in embryos lacking outward discernable phenotypes, and we additionally resolved disruptions in certain peripheral neural structures, altered establishment and migration of neural crest, and defects in ectodermal multiciliated cells. The use of two distinct morpholinos, as well as rescue approaches, indicated the specificity of these effects. Our results point to the requirement of Pkp3 in amphibian embryogenesis, with functional roles in a number of tissue types.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: William A
authors.initials: WA
authors.lastname: Munoz
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Kloc
authors.forename: Kyucheol
authors.initials: K
authors.lastname: Cho
authors.forename: Moonsup
authors.initials: M
authors.lastname: Lee
authors.forename: Ilse
authors.initials: I
authors.lastname: Hofmann
authors.forename: Amy
authors.initials: A
authors.lastname: Sater
authors.forename: Kris
authors.initials: K
authors.lastname: Vleminckx
authors.forename: Pierre D
authors.initials: PD
authors.lastname: McCrea
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D051177:Catenins / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement; D003896:Desmosomes / Q000378:metabolism; D004475:Ectoderm / Q000166:cytology / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D051379:Mice; D008969:Molecular Sequence Data; D009432:Neural Crest / Q000166:cytology / Q000378:metabolism*; D051191:Plakophilins / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014982:Xenopus laevis / Q000196:embryology* / Q000378:metabolism
chemical_list: D015820:Cadherins; D051177:Catenins; D051191:Plakophilins; D012333:RNA, Messenger