title: Drosophila p120catenin plays a supporting role in cell adhesion but is not an essential adherens junction component.
abstract: Cadherin-catenin complexes, localized to adherens junctions, are essential for cell-cell adhesion. One means of regulating adhesion is through the juxtamembrane domain of the cadherin cytoplasmic tail. This region is the binding site for p120, leading to the hypothesis that p120 is a key regulator of cell adhesion. p120 has also been suggested to regulate the GTPase Rho and to regulate transcription via its binding partner Kaiso. To test these hypothesized functions, we turned to Drosophila, which has only a single p120 family member. It localizes to adherens junctions and binds the juxtamembrane region of DE-cadherin (DE-cad). We generated null alleles of p120 and found that mutants are viable and fertile and have no substantial changes in junction structure or function. However, p120 mutations strongly enhance mutations in the genes encoding DE-cadherin or Armadillo, the beta-catenin homologue. Finally, we examined the localization of p120 during embryogenesis. p120 localizes to adherens junctions, but its localization there is less universal than that of core adherens junction proteins. Together, these data suggest that p120 is an important positive modulator of adhesion but that it is not an essential core component of adherens junctions.
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Myster
authors.forename: Robert
authors.initials: R
authors.lastname: Cavallo
authors.forename: Charles T
authors.initials: CT
authors.lastname: Anderson
authors.forename: Donald T
authors.initials: DT
authors.lastname: Fox
authors.forename: Mark
authors.initials: M
authors.lastname: Peifer
mesh_terms: D022005:Adherens Junctions / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D051186:Armadillo Domain Proteins; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D051177:Catenins; D002448:Cell Adhesion / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000172:deficiency* / Q000235:genetics; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000166:cytology / Q000378:metabolism; D019143:Evolution, Molecular; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010750:Phosphoproteins / Q000172:deficiency* / Q000235:genetics; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors; D000095002:Delta Catenin
chemical_list: C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; D018076:DNA, Complementary; D029721:Drosophila Proteins; D010750:Phosphoproteins; D015534:Trans-Activators; D014157:Transcription Factors; D000095002:Delta Catenin