TY - JOUR
T1 - Plakoglobin binding by human Dsg3 (pemphigus vulgaris antigen) in keratinocytes requires the cadherin-like intracytoplasmic segment
AU - Roh, J. Y.
AU - Stanley, J. R.
PY - 1995
Y1 - 1995
N2 - Desmogleins are transmembrane desmosomal cadherins. Two desmogleins, Dsg3 and Dsg1, have been shown to bind plakoglobin, an intracytoplasmic (IC) desmosomal plaque protein. This binding may be critical for desmosome assembly or stability. The IC domain of desmogleins consists of subdomains that are either desmoglein specific or homologous with the IC region of classical cadherins. Here we identify the domains of human Dsg3 that are critical for plakoglobin binding in human keratinocytes. We constructed eukaryotic expression vectors containing chimeric cDNAs that encode the extracellular domain of mouse E-cadherin (Ecad) with the transmembrane and IC domains of Dsg3, with increasing truncations eliminating various IC subdomains from the carboxy-terminus. These constructs were used for transient transfection of HaCaT cells. Extracts were subjected to immunoprecipition with an anti-mouse Ecad antibody (that does not precipitate human Ecad), thus precipitating the chimeric protein and any tightly associated plakoglobin. Co-precipitation of plakoglobin was confirmed by immunoblotting. These data show that the desmoglein-specific IC subdomains are not necessary for plakoglobin binding, but the carboxy-terminal 87 amino acids of the IC-cadherin-like segment subdomain are critical. Finally, we confirmed these results outside cells with in vitro transcription and translation, which also demonstrates that the Dsg3-plakoglobin interaction is direct and does not depend on other cellular factors. These results underscore the importance of a region, highly conserved in all desmogleins, in the carboxy terminus of the IC-cadherin-like subdomain for the localization of plakoglobin to desmosomes.
AB - Desmogleins are transmembrane desmosomal cadherins. Two desmogleins, Dsg3 and Dsg1, have been shown to bind plakoglobin, an intracytoplasmic (IC) desmosomal plaque protein. This binding may be critical for desmosome assembly or stability. The IC domain of desmogleins consists of subdomains that are either desmoglein specific or homologous with the IC region of classical cadherins. Here we identify the domains of human Dsg3 that are critical for plakoglobin binding in human keratinocytes. We constructed eukaryotic expression vectors containing chimeric cDNAs that encode the extracellular domain of mouse E-cadherin (Ecad) with the transmembrane and IC domains of Dsg3, with increasing truncations eliminating various IC subdomains from the carboxy-terminus. These constructs were used for transient transfection of HaCaT cells. Extracts were subjected to immunoprecipition with an anti-mouse Ecad antibody (that does not precipitate human Ecad), thus precipitating the chimeric protein and any tightly associated plakoglobin. Co-precipitation of plakoglobin was confirmed by immunoblotting. These data show that the desmoglein-specific IC subdomains are not necessary for plakoglobin binding, but the carboxy-terminal 87 amino acids of the IC-cadherin-like segment subdomain are critical. Finally, we confirmed these results outside cells with in vitro transcription and translation, which also demonstrates that the Dsg3-plakoglobin interaction is direct and does not depend on other cellular factors. These results underscore the importance of a region, highly conserved in all desmogleins, in the carboxy terminus of the IC-cadherin-like subdomain for the localization of plakoglobin to desmosomes.
UR - http://www.scopus.com/inward/record.url?scp=0029019126&partnerID=8YFLogxK
U2 - 10.1111/1523-1747.ep12606963
DO - 10.1111/1523-1747.ep12606963
M3 - Article
C2 - 7738346
AN - SCOPUS:0029019126
SN - 0022-202X
VL - 104
SP - 720
EP - 724
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
IS - 5
ER -