A1 Refereed original research article in a scientific journal

Keratins Stabilize Hemidesmosomes through Regulation of beta 4-Integrin Turnover




AuthorsSeltmann K, Cheng F, Wiche G, Eriksson JE, Magin TM

PublisherNATURE PUBLISHING GROUP

Publication year2015

JournalJournal of Investigative Dermatology

Journal name in sourceJOURNAL OF INVESTIGATIVE DERMATOLOGY

Journal acronymJ INVEST DERMATOL

Volume135

Issue6

First page 1609

Last page1620

Number of pages12

ISSN0022-202X

eISSN1523-1747

DOIhttps://doi.org/10.1038/jid.2015.46(external)


Abstract

Epidermal integrity and wound healing depend on remodeling of cell-matrix contacts including hemidesmosomes. Mutations in beta 4-integrin and plectin lead to severe epidermolysis bullosa (EB). Whether mutations in keratins K5 or K14, which cause EB simplex, also compromise cell-matrix adhesion through altering hemidesmosomal components is not well investigated. In particular, the dependence of beta 4-integrin endocytosis and turnover on keratins remains incompletely understood. Here, we show that the absence of keratins causes loss of plectin-beta 4-integrin interaction and elevated beta 4-integrin phosphorylation at Ser1354 and Ser1362. This triggered a caveolin-dependent endocytosis of beta 4-integrin but not of other integrins through Rab5 and Rab11 compartments in keratinocytes. Expressing a phospho-deficient beta 4-integrin mutant reduces beta 4-integrin endocytosis and rescues plectin localization in keratin-free cells. beta 4-integrin phosphorylation in the absence of keratins resulted from elevated Erk1/2 activity downstream of increased EGFR and PKC alpha signaling. Further, increased Erk1/2 phosphorylation and altered plectin localization occur in keratin-deficient mouse epidermis in vivo. Strikingly, expression of the K14-R125P EBS mutant also resulted in plectin mislocalization and elevated beta 4-integrin turnover, suggesting disease relevance. Our data underscore a major role of keratins in controlling beta 4-integrin endocytosis involving a plectin-Erk1/2-dependent mechanism relevant for epidermal differentiation and pathogenesis.




Last updated on 2024-26-11 at 14:25