Related Experiment Video
Updated: Aug 11, 2026
Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro
Published on: July 17, 2018
Molecular cloning of Porimin, a novel cell surface receptor mediating oncotic cell death
1Division of Tumor Immunology, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
Anti-Porimin (Pro-oncosis receptor inducing membrane injury) mAb mediates oncosis-like cell death in Jurkat cells. Porimin cDNA was isolated from a Jurkat cell cDNA library by COS cell-expression cloning. The 3,337-bp cDNA has an ORF of 567 bp, encoding a type I transmembrane protein of 189 amino acids. The extracellular domain of Porimin contains many O-linked and seven N-linked glycosylation sites that define it as a new member of the mucin family. COS7 and 293 cells transiently transfected with Porimin cDNA were specifically recognized by anti-Porimin Ab in cell staining and immunoblotting experiments. When expressed in Jurkat cells, a His-tagged Porimin cDNA construct resulted in the generation of a specific 110-kDa-size protein that matched the molecular mass of the endogenous Porimin protein. Crosslinking of the Porimin receptor expressed on COS7 transfectants resulted in the loss of cell membrane integrity and cell death as measured by the leakage of intracellular lactate dehydrogenase. Both COS7 and 293 cells expressing transfected Porimin at a relatively high level lost their ability to adhere to culture dishes, suggesting a role for Porimin in cell adhesion. The Porimin gene was mapped to human chromosome 11q22.1 and is composed of four exons spanning 133 kb of genomic DNA.
Insights
Anti-Porimin monoclonal antibody induces oncosis-like cell death by targeting the Porimin receptor, a mucin family member involved in cell adhesion. This study characterizes Porimin
Area of Science:
- Molecular Biology
- Cell Biology
- Immunology
Background:
- Porimin (Pro-oncosis receptor inducing membrane injury) is a type I transmembrane protein identified as a new member of the mucin family.
- Porimin possesses multiple glycosylation sites, suggesting its potential role in cellular processes.
- The function and cellular localization of Porimin were previously uncharacterized.
Purpose of the Study:
- To isolate and characterize the Porimin cDNA and protein.
- To investigate the role of Porimin in cell death and cell adhesion.
- To determine the chromosomal localization of the Porimin gene.
Main Methods:
- COS cell-expression cloning was used to isolate Porimin cDNA from a Jurkat cell library.
- Transient transfection of COS7 and 293 cells with Porimin cDNA, followed by cell staining and immunoblotting with anti-Porimin antibody.
- Functional assays including lactate dehydrogenase leakage measurement and cell adhesion assays were performed on transfected cells.
Main Results:
- A 3,337-bp cDNA encoding a 189-amino acid type I transmembrane protein was identified.
- Porimin expression in Jurkat cells produced a 110-kDa protein consistent with the endogenous protein.
- Crosslinking of Porimin induced oncosis-like cell death and loss of cell adhesion in transfected cells.
Conclusions:
- Porimin is a novel mucin family member that mediates oncosis-like cell death.
- Porimin plays a role in regulating cell membrane integrity and cell adhesion.
- The Porimin gene is located on human chromosome 11q22.1.
