N-Glycosylation of integrin α5 acts as a switch for EGFR-mediated complex formation of integrin α5β1 to α6β4

Sci Rep. 2016 Sep 19:6:33507. doi: 10.1038/srep33507.

Abstract

N-Glycosylation of integrin α5β1 is involved in multiple cell behaviors. We previously reported that the N-glycosylations of the calf domain on integrin α5 (S3-5,10-14) are essential for its inhibitory effect on EGFR signaling in regulating cell proliferation. However, the importance of the individual N-glycosylation and the underlying mechanisms of inhibition remain unclear. Here, we characterize the S3-5,10-14 mutants in detail and found that the N-glycosylation of site-11 (Asn712) is key for cell growth. The restoration of site-11, unlike the other individual sites, significantly suppressed cell growth and EGFR signaling in a manner that was similar to that of wild-type (WT). Mechanistically, this N-glycosylation inhibited the response abilities upon EGF stimulation and EGFR dimerization. Interestingly, we found this N-glycosylation controlled the EGFR complex formation with integrin α5β1 or α6β4; i.e., the loss of site-11 switched EGFR-α5β1 to EGFR-α6β4, which is well known to promote cellular signaling for cell growth. Moreover, the site-11 N-glycan exhibited a more branching structure compared with other sites, which may be required for EGFR-α5β1 formation. Taken together, these data clearly demonstrate that the site-11 N-glycosylation on α5 is most important for its inhibitory effect on EGFR signaling, which may provide a novel regulatory mechanism for crosstalks between integrins and EGFR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Cell Proliferation
  • Cricetinae
  • Cricetulus
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / metabolism*
  • Glycosylation
  • HeLa Cells
  • Humans
  • Integrin alpha5 / chemistry
  • Integrin alpha5 / metabolism*
  • Integrin alpha5beta1 / metabolism*
  • Integrin alpha6beta4 / metabolism*
  • Models, Biological
  • Mutant Proteins / chemistry
  • Mutant Proteins / metabolism
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism
  • Protein Domains
  • Protein Multimerization
  • Protein Subunits / chemistry
  • Protein Subunits / metabolism
  • Signal Transduction

Substances

  • Integrin alpha5
  • Integrin alpha5beta1
  • Integrin alpha6beta4
  • Mutant Proteins
  • Polysaccharides
  • Protein Subunits
  • Epidermal Growth Factor
  • ErbB Receptors