Home
Resource
Osteopontin and cell adhesion: role of post-translational modifications and the C-terminal region
PDF
PDF format is widely accepted and good for printing.
Plug-in required
PDF-1(872.44 kb)
Citation & Export
View Usage Statistics
Staff View

Citation & Export
Hide

Simple citation

Kazanecki, Christian Charles. Osteopontin and cell adhesion: role of post-translational modifications and the C-terminal region. Retrieved from https://doi.org/doi:10.7282/T3GF0TXZ

Export

Click here for information about Citation Management Tools at Rutgers.

Statistics
Hide

Description

TitleOsteopontin and cell adhesion: role of post-translational modifications and the C-terminal region
NameKazanecki, Christian Charles (author); Denhardt, David (chair); Fong, Dunne (internal member); Xiao, Gutian (internal member); Sahota, Amrik (internal member); Riman, Richard (outside member); Rutgers University; Graduate School-New Brunswick
Date Created2007
Other Date2007 (degree)
SubjectMicrobiology and Molecular Genetics, Osteopontin, Cell adhesion molecules, Phosphoproteins, C-peptide
Extentxii, 109 pages
DescriptionOsteopontin (OPN) is an integrin-binding secreted phosphoglycoprotein found in many tissues and body fluids, where it acts as both a soluble cytokine and a component of mineralized matrices. It exhibits a broad range of functional activities in physiological and pathological processes, many of which are influenced by post-translational modifications. OPN is highly modified by phosphorylation and glycosylation that can vary depending on the source. This study identified two different forms of OPN produced by murine ras-transformed fibroblasts (FbOPN) and differentiating osteoblasts (ObOPN) based on the reactivity of a panel of anti-OPN monoclonal antibodies. By enzymatic dephosphorylation, mass, and sequence analyses, it was shown that FbOPN contained approximately four phosphate groups distributed over 17 potential phosphorylation sites, whereas ObOPN contained approximately 21 phosphate groups distributed over 27 sites. This is the first extensive characterization of OPN produced by transformed cells, and the FbOPN form is the least modified form of OPN that has been characterized to date.

The forms of OPN also differed in their ability to support adhesion of human MDA-MB-435 tumor cells and mouse 275-3-2 ras-transformed fibroblasts. The MDA-MB-435 cells bound with approximately 60% greater efficiency to the FbOPN than ObOPN, whereas the 275-3-2 cells bound the ObOPN with 35% greater efficiency than FbOPN. Inhibition of adhesion with an Arg-Gly-Asp (RGD)-containing peptide inhibited the binding of both lines to the OPN forms, suggesting that different integrins preferentially bind to OPN based upon its phosphorylation state.

This study has also identified a potential role for a novel region of OPN in cell adhesion. Two anti-osteopontin monoclonal antibodies, both of which recognize the C-terminal region of OPN, were shown to inhibit MDA-MB-435 cell adhesion to recombinant human OPN. Synthetic peptides corresponding to this region were bound by cells using a flow cytometry assay, suggesting a receptor interaction in this region of OPN. This interaction is hypothesized to be a signaling interaction because cells were not able to adhere to the synthetic C-terminal peptides and adhesion in the presence of these soluble peptides was not affected.
NotePh.D.
NoteIncludes bibliographical references (p. 86-107).
Genretheses, ETD doctoral
Persistent URLhttps://doi.org/doi:10.7282/T3GF0TXZ
LanguageEnglish
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.
Version 8.5.5
Rutgers University Libraries - Copyright ©2024