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Updated: Jul 13, 2026
10:43
Methods to Study Mrp4-containing Macromolecular Complexes in the Regulation of Fibroblast Migration
Published on: May 19, 2016
Progesterone receptor or cytoskeletal protein?
Gemma Madsen1, David A Macintyre, Sam Mesiano
1Mothers and Babies Research Centre, Hunter Medical Research Institute, University of Newcastle, John Hunter Hospital, Newcastle, NSW, Australia. gemma.madsen@newcastle.edu.au
Reproductive Sciences (Thousand Oaks, Calif.)
|July 20, 2007
Summary
The nuclear progesterone receptor (nPR) antibody sc-538 cross-reacts with common cytoskeletal proteins, leading to misidentification of nPR isoforms and confusing progesterone response research.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Endocrinology
Background:
- Immunoblotting is crucial for identifying nuclear progesterone receptor (nPR) isoforms.
- Antibody specificity is essential for accurate results in immunoblotting techniques.
- Previous studies have utilized the nPR antibody sc-538.
Purpose of the Study:
- To investigate the specificity of the nPR antibody sc-538.
- To determine if the antibody cross-reacts with other proteins in human myometrium.
- To clarify potential misinterpretations in progesterone response literature.
Main Methods:
- Immunoblotting of human myometrial protein lysates and a myometrial cell line (PHM1-31) using sc-538.
- Extraction and identification of immunoreactive bands via 1-dimensional liquid chromatography mass spectrometry.
- Immunoprecipitation with sc-538 followed by immunoblotting with antibodies against cytoskeletal proteins.
Main Results:
- The nPR antibody sc-538 detected two bands at 100 kDa and 55 kDa.
- Mass spectrometry identified alpha-actinin in the 100 kDa band.
- Vimentin and desmin were identified as the dominant proteins in the 55 kDa band.
- Immunoprecipitation confirmed the presence of alpha-actinin, vimentin, and desmin.
Conclusions:
- The nPR antibody sc-538 exhibits cross-reactivity with cytoskeletal proteins, specifically alpha-actinin, vimentin, and desmin.
- Misinterpretation of these cross-reactive bands as nPR isoforms can lead to erroneous conclusions.
- This cross-reactivity has likely contributed to confusion in the literature regarding progesterone receptor function and response.
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