This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rabinovitz, I. Articles by Mercurio, A. M. Search for Related Content PubMed PubMed Citation Articles by Rabinovitz, I. Articles by Mercurio, A. M.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, May 2004, p. 4351-4360, Vol. 24, No. 10
0270-7306/04/$08.00+0     DOI: 10.1128/MCB.24.10.4351-4360.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Protein Kinase C- Phosphorylation of Specific Serines in the Connecting Segment of the ß4 Integrin Regulates the Dynamics of Type II Hemidesmosomes

Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115,

Received 9 October 2003/ Returned for modification 2 December 2003/ Accepted 18 February 2004

Although the regulation of hemidesmosome dynamics during processes such as epithelial migration, wound healing, and carcinoma invasion is important, the mechanisms involved are poorly understood. The integrin 6ß4 is an essential component of the hemidesmosome and a target of such regulation. Epidermal growth factor (EGF) can induce hemidesmosome disassembly by a mechanism that involves serine phosphorylation of the ß4 integrin subunit. Using a combination of biochemical and mutational analyses, we demonstrate that EGF induces the phosphorylation of three specific serine residues (S₁₃₅₆, S₁₃₆₀, and S₁₃₆₄) located within the connecting segment of the ß4 subunit and that phosphorylation on these residues accounts for the bulk of ß4 phosphorylation stimulated by EGF. Importantly, phosphorylation of these serines is critical for the ability of EGF to disrupt hemidesmosomes. Using COS-7 cells, which assemble hemidesmosomes type II upon exogenous expression of the 6ß4 integrin, we observed that expression of a ß4 construct containing SerAla mutations of S₁₃₅₆, S₁₃₆₀, and S₁₃₆₄ reduced the ability of EGF to disrupt hemidesmosomes and that this effect appears to involve cooperation among these phosphorylation sites. Moreover, expression of SerAsp mutants that mimic constitutive phosphorylation reduced hemidesmosome formation. Protein kinase C- (PKC-) is the kinase responsible for phosphorylating at least two of these serines, based on in vitro kinase assays, peptide mapping, and mutational analysis. Together, these results highlight the importance of serine phosphorylation in regulating type II hemidesmosome disassembly, implicate a cluster of serine residues within the connecting segment of ß4, and argue for a key role for PKC- in regulating these structures.

This article has been cited by other articles:

• Yang, X. H., Richardson, A. L., Torres-Arzayus, M. I., Zhou, P., Sharma, C., Kazarov, A. R., Andzelm, M. M., Strominger, J. L., Brown, M., Hemler, M. E. (2008). CD151 Accelerates Breast Cancer by Regulating {alpha}6 Integrin Function, Signaling, and Molecular Organization. Cancer Res. 68: 3204-3213 [Abstract] [Full Text]  
• Thingholm, T. E., Jensen, O. N., Robinson, P. J., Larsen, M. R. (2008). SIMAC (Sequential Elution from IMAC), a Phosphoproteomics Strategy for the Rapid Separation of Monophosphorylated from Multiply Phosphorylated Peptides. Mol. Cell. Proteomics 7: 661-671 [Abstract] [Full Text]  
• Wilhelmsen, K., Litjens, S. H.M., Kuikman, I., Margadant, C., van Rheenen, J., Sonnenberg, A. (2007). Serine Phosphorylation of the Integrin beta4 Subunit Is Necessary for Epidermal Growth Factor Receptor induced Hemidesmosome Disruption. Mol. Biol. Cell 18: 3512-3522 [Abstract] [Full Text]  
• Folgiero, V., Bachelder, R. E., Bon, G., Sacchi, A., Falcioni, R., Mercurio, A. M. (2007). The {alpha}6{beta}4 Integrin Can Regulate ErbB-3 Expression: Implications for {alpha}6{beta}4 Signaling and Function. Cancer Res. 67: 1645-1652 [Abstract] [Full Text]  
• Wilhelmsen, K., Litjens, S. H.M., Sonnenberg, A. (2006). Multiple Functions of the Integrin {alpha}6{beta}4 in Epidermal Homeostasis and Tumorigenesis. Mol. Cell. Biol. 26: 2877-2886 [Full Text]  
• Yoon, S.-O., Shin, S., Mercurio, A. M. (2005). Hypoxia Stimulates Carcinoma Invasion by Stabilizing Microtubules and Promoting the Rab11 Trafficking of the {alpha}6{beta}4 Integrin. Cancer Res. 65: 2761-2769 [Abstract] [Full Text]