Formation of the 67-kDa laminin receptor by acylation of the precursor

Simona Butò, Elda Tagliabue, Elena Ardini, Alessandra Magnifico, Cristina Ghirelli, Frédéric Van Den Brûle, Vincent Castronovo, Maria I. Colnaghi, Mark E. Sobel, Sylvie Ménard

Research output: Contribution to journalArticle

Abstract

Even though the involvement of the 67-kDa laminin receptor (67LR) in tumor invasiveness has been clearly demonstrated, its molecular structure remains an open problem, since only a full-length gene encoding a 37-kDa precursor protein (37LRP) has been isolated so far. A pool of recently obtained monoclonal antibodies directed against the recombinant 37LRP molecule was used to investigate the processing that leads to the formation of the 67-kDa molecule. In soluble extracts of A431 human carcinoma cells, these reagents recognize the precursor molecule as well as the mature 67LR and a 120-kDa molecule. The recovery of these proteins was found to be strikingly dependent upon the cell solubilization conditions: the 67LR is soluble in NP-40-lysis buffer whereas the 37LRP is NP-40-insoluble. Inhibition of 67LR formation by cerulenin indicates that acylation is involved in the processing of the receptor. It is likely a palmitoylation process, as indicated by sensitivity of NP-40-soluble extracts to hydroxylamine treatment. Immunoblotting assays performed with a polyclonal serum directed against galectin3 showed that both the 67- and the 120-kDa proteins carry galectin3 epitopes whereas the 37LRP does not. These data suggest that the 67LR is a heterodimer stabilized by strong intramolecular hydrophobic interactions, carried by fatty acids bound to the 37LRP and to a galectin3 cross-reacting molecule.

Original languageEnglish
Pages (from-to)244-251
Number of pages8
JournalJournal of Cellular Biochemistry
Volume69
Issue number3
DOIs
Publication statusPublished - Jun 1 1998

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Keywords

  • Acylation
  • Monomeric laminin receptor
  • Receptor maturation

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology

Cite this

Butò, S., Tagliabue, E., Ardini, E., Magnifico, A., Ghirelli, C., Van Den Brûle, F., Castronovo, V., Colnaghi, M. I., Sobel, M. E., & Ménard, S. (1998). Formation of the 67-kDa laminin receptor by acylation of the precursor. Journal of Cellular Biochemistry, 69(3), 244-251. https://doi.org/10.1002/(SICI)1097-4644(19980601)69:3<244::AID-JCB2>3.0.CO;2-R