Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-9-15
pubmed:abstractText
A number of papers have been published on the clinical correlation of the expression of the 67 kDa laminin binding protein (LBP) with the metastatic potential of solid tumors. Both mRNA and protein expression levels have been reported, but both the relationship between them and the molecular nature of the 67 kDa surface product remain unclear. We have utilized a homotypic overexpression system to investigate the cell surface presentation of the 67 kDa LBP and the contribution of this protein to the invasive phenotype of cultured cell lines. We report here that the cellular mRNA levels do not directly reflect the levels of the 67 kDa LBP observed on the cell surface in this overexpression system. Methotrexate amplification of transfected plasmids expressing the 67 kDa LBP leads to an initial elevation of both the LBP mRNA and surface protein levels. This is accompanied by an altered, more flattened, cell morphology. Later, apparent adaptation of the cells to methotrexate is accompanied by a down-regulation of the surface expression of the protein. mRNA levels, however, remain elevated. A nine amino acid sequence, CDPGYIGSR (peptide 11), within the beta chain of laminin 1 has been identified as a probable binding domain for the 67 kDa LBP. Previous studies have identified a region of the 67 kDa LBP which may be involved in laminin interaction, although not necessarily via the peptide 11 domain. We have identified a second site within the amino acid coding sequence of the 67 kDa LBP which also shows biological activity both in vitro and in vivo. A peptide with this sequence, LBP residues 205-229, binds laminin-1 in a peptide 11 inhibitable manner. The receptor-derived peptide modulates invasion of basement membrane matrix in vitro and inhibits experimental lung colony formation when injected along with B16BL6 mouse melanoma cells. However, pretreatment of the melanoma cells with the peptide enhances lung colony formation. Thus, the interaction of the 67 kDa LBP with basement membrane matrix appears to involve a complex series of events including multiple adhesive sites and tight regulation of cell surface expression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0262-0898
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
357-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7641420-Amino Acid Sequence, pubmed-meshheading:7641420-Animals, pubmed-meshheading:7641420-Antibody Specificity, pubmed-meshheading:7641420-Binding Sites, pubmed-meshheading:7641420-Blotting, Western, pubmed-meshheading:7641420-CHO Cells, pubmed-meshheading:7641420-Cricetinae, pubmed-meshheading:7641420-Female, pubmed-meshheading:7641420-Laminin, pubmed-meshheading:7641420-Lung Neoplasms, pubmed-meshheading:7641420-Melanoma, Experimental, pubmed-meshheading:7641420-Membrane Proteins, pubmed-meshheading:7641420-Mice, pubmed-meshheading:7641420-Mice, Inbred Strains, pubmed-meshheading:7641420-Molecular Sequence Data, pubmed-meshheading:7641420-Neoplasm Invasiveness, pubmed-meshheading:7641420-Peptide Biosynthesis, pubmed-meshheading:7641420-Peptide Fragments, pubmed-meshheading:7641420-Peptides, pubmed-meshheading:7641420-Protein Precursors, pubmed-meshheading:7641420-RNA, Messenger, pubmed-meshheading:7641420-Receptors, Laminin, pubmed-meshheading:7641420-Sequence Homology, Amino Acid, pubmed-meshheading:7641420-Tumor Cells, Cultured
pubmed:year
1995
pubmed:articleTitle
Control pathways of the 67 kDa laminin binding protein: surface expression and activity of a new ligand binding domain.
pubmed:affiliation
Department of Microbiology, Montana State University, Bozeman 59717, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.