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Radiolabeling and Quantification of Cellular Levels of Phosphoinositides by High Performance Liquid Chromatography-coupled Flow Scintillation
Published on: January 6, 2016
STIM1: a novel phosphoprotein located at the cell surface.
S S Manji1, N J Parker, R T Williams
1Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia. manjis@cryptic.rch.unimelb.edu.au
Biochimica Et Biophysica Acta
|September 27, 2000
Summary
Stromal interaction molecule 1 (STIM1) acts as a tumor suppressor gene, inhibiting growth in various cancer cell lines. This protein is found on the cell surface and is modified through phosphorylation and glycosylation.
Area of Science:
- Molecular Biology
- Cancer Research
- Cell Biology
Background:
- STIM1 is identified as a novel candidate tumor suppressor gene.
- It maps to human chromosome region 11p15.5, a locus frequently altered in malignancies.
- STIM1 overexpression induces growth arrest in rhabdoid tumor, rhabdomyosarcoma, and myoblast cell lines.
Purpose of the Study:
- To investigate the cellular localization and characteristics of STIM1.
- To confirm the role of STIM1 as a potential tumor suppressor.
- To explore post-translational modifications of STIM1.
Main Methods:
- Immunofluorescence and cell surface biotinylation using specific antibodies.
- Western blot analysis for protein expression.
- Analysis of post-translational modifications (phosphorylation, glycosylation).
Main Results:
- STIM1 is localized to the cell surface of K562 cells.
- The 90-kDa STIM1 protein is ubiquitously expressed in human cells and tumor lines.
- Evidence of post-translational modifications, including serine-predominant phosphorylation and N-linked glycosylation, was found.
Conclusions:
- STIM1 functions as a tumor growth suppressor.
- STIM1 is a ubiquitously expressed, cell-surface phosphoprotein with regulatory potential.
- STIM1 undergoes post-translational modifications, suggesting complex regulation.
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