Palmitoylation of Desmoglein 2 Is a Regulator of Assembly Dynamics and Protein Turnover

• Type of Material: Article
• Authors: Brett J. Roberts, University of Nebraska; Robert A. Svoboda, University of Nebraska; Andrew M. Overmiller, Thomas Jefferson University; Joshua D. Lewis, Emory University; Andrew Kowalczyk, Emory University; My G. Mahoney, Thomas Jefferson University; Keith R. Johnson, University of Nebraska; James K. Wahl, University of Nebraska
• Language: English
• Date: 2016-11-25
• Publisher: American Society for Biochemistry and Molecular Biology
• Publication Version: Final Published Version
• Copyright Statement: © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1074/jbc.M116.739458
• Title of Journal or Parent Work: Journal of Biological Chemistry
• ISSN: 0021-9258
• Volume: 291
• Issue: 48
• Start Page: 24857
• End Page: 24865
• Grant/Funding Information: The research reported in this publication was supported by an Institutional Development Award (Grant 5P30GM106397 to K. R. J.), by NIAMS, National Institutes of Health Grant R15AR065074 (to J. K. W.), and by National Institutes of Health Grants R01AR048266 (to A. P. K.) and F31AR066476 (to J. D. L.).; Microscopy images were acquired and processed at the University of Nebraska Medical Center Advanced Microscopy Core Facility supported by the Nebraska Research Initiative and the Eppley Cancer Center (P30CA036727) and Nebraska Center for Cellular Signaling CoBRE (National Institutes of Health P30GM106397).; The anti-Lamp-1 hybridoma supernatant developed by J. T. August and J. E. K. Hildreth was obtained from the Developmental Studies Hybridoma Bank, created by NICHD, National Institutes of Health and maintained at the Department of Biology, University of Iowa, Iowa City, IA 52242.
• Keywords: JUNCTIONS; IDENTIFICATION; ACYLATION; PLASMA-MEMBRANE; DESMOPLAKIN; Biochemistry & Molecular Biology; DIFFERENTIATION; CELLS; Desmosome; P120 CATENIN; Cadherin; Protein palmitoylation; Life Sciences & Biomedicine; DESMOSOME DYNAMICS; DISEASE; Desmoglein; Lipid raft; Science & Technology
• Research Categories: Health Sciences, Dentistry; Biology, Cell

Abstract

Desmosomes are prominent adhesive junctions present between many epithelial cells as well as cardiomyocytes. The mechanisms controlling desmosome assembly and remodeling in epithelial and cardiac tissue are poorly understood. We recently identified protein palmitoylation as a mechanism regulating desmosome dynamics. In this study, we have focused on the palmitoylation of the desmosomal cadherin desmoglein-2 (Dsg2) and characterized the role that palmitoylation of Dsg2 plays in its localization and stability in cultured cells. We identified two cysteine residues in the juxtamembrane (intracellular anchor) domain of Dsg2 that, when mutated, eliminate its palmitoylation. These cysteine residues are conserved in all four desmoglein family members. Although mutant Dsg2 localizes to endogenous desmosomes, there is a significant delay in its incorporation into junctions, and the mutant is also present in a cytoplasmic pool. Triton X-100 solubility assays demonstrate that mutant Dsg2 is more soluble than wild-type protein. Interestingly, trafficking of the mutant Dsg2 to the cell surface was delayed, and a pool of the non-palmitoylated Dsg2 co-localized with lysosomal markers. Taken together, these data suggest that palmitoylation of Dsg2 regulates protein transport to the plasma membrane. Modulation of the palmitoylation status of desmosomal cadherins can affect desmosome dynamics.