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Updated: Jul 27, 2025
Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies
Published on: March 6, 2013
Structural, topological, and functional characterization of transmembrane proteins TMEM213, 207, 116, 72 and 30B
Joanna Wesoly1, Natalia Pstrąg1, Kamil Derylo2
1Laboratory of High Throughput Technologies, Adam Mickiewicz University Poznan, Poland.
Abstract:
Due to their involvement in the development of various cancers Transmembrane Proteins (TMEMs) are the focus of many recent studies. Previously we reported TMEM de-regulation in clear cell Renal Cell Carcinoma (ccRCC) with TMEM213, 207, 116, 72 and 30B being among the most downregulated on mRNA level. TMEM down-regulation was also more pronounced in advanced ccRCC tumors and was potentially linked to clinical parameters such as: metastasis (TMEM72 and 116), Fuhrman grade (TMEM30B) and overall survival (TMEM30B). To further investigate these findings, first, we set off to prove experimentally that selected TMEMs are indeed membrane-bound as predicted in silico, we verified the presence of signaling peptides on their N-termini, orientation of TMEMs within the membrane and validated their predicted cellular localization. To investigate the potential role of selected TMEMs in cellular processes overexpression studies in HEK293 and HK-2 cell lines were carried out. Additionally, we tested TMEM isoform expression in ccRCC tumors, identified mutations in TMEM genes and examined chromosomal aberrations in their loci. We confirmed the membrane-bound status of all selected TMEMs, assigned TMEM213, and 207 to early endosomes, TMEM72 to early endosomes and plasma membrane, TMEM116 and 30B to the endoplasmic reticulum. The N-terminus of TMEM213 was found to be exposed to the cytoplasm, the C-terminus of TMEM207, 116 and 72 were directed toward the cytoplasm, and both termini of TMEM30B faced the cytoplasm. Interestingly, TMEM mutations and chromosomal aberrations were infrequent in ccRCC tumors, yet we identified potentially damaging mutations in TMEM213 and TMEM30B and found deletions in the TMEM30B locus in nearly 30% of the tumors. Overexpression studies suggested selected TMEMs may take part in carcinogenesis processes such as cell adhesion, regulation of epithelial cell proliferation, and regulation of adaptive immune response, which could indicate a link to the development and progression of ccRCC.
Insights
Transmembrane proteins (TMEMs) are downregulated in clear cell renal cell carcinoma (ccRCC), particularly in advanced stages. These TMEMs, confirmed as membrane-bound, may play roles in cancer development through processes like cell adhesion and proliferation.
Area of Science:
- Molecular Biology
- Oncology
- Genetics
Background:
- Transmembrane proteins (TMEMs) are implicated in cancer development.
- Previous studies reported TMEM deregulation, specifically downregulation, in clear cell Renal Cell Carcinoma (ccRCC).
- Downregulation of specific TMEMs (TMEM213, 207, 116, 72, 30B) correlated with advanced ccRCC, metastasis, Fuhrman grade, and survival.
Purpose of the Study:
- To experimentally validate the membrane-bound status and localization of selected TMEMs.
- To investigate the potential role of TMEMs in carcinogenesis through overexpression studies.
- To analyze TMEM gene expression, mutations, and chromosomal aberrations in ccRCC tumors.
Main Methods:
- In silico prediction validation for membrane-bound status and signaling peptides.
- Experimental verification of TMEM N-termini orientation and cellular localization (HEK293, HK-2 cells).
- Overexpression studies, TMEM isoform expression analysis, mutation identification, and chromosomal aberration examination in ccRCC tumors.
Main Results:
- All selected TMEMs were confirmed as membrane-bound.
- Specific TMEMs localized to early endosomes (TMEM213, 207), plasma membrane (TMEM72), and endoplasmic reticulum (TMEM116, 30B).
- Potentially damaging mutations in TMEM213 and TMEM30B, and TMEM30B locus deletions (approx. 30%) were found; overexpression suggested roles in cell adhesion, proliferation, and immune response.
Conclusions:
- Selected TMEMs are confirmed membrane proteins with specific cellular localizations relevant to ccRCC.
- Despite infrequent mutations, TMEM30B locus deletions and specific TMEM mutations suggest a role in ccRCC pathogenesis.
- TMEMs may contribute to ccRCC development and progression via carcinogenesis pathways, including cell adhesion and proliferation regulation.
