Related Experiment Videos
Molecular cloning and expression of the type 1 and type 2 murine receptors for tumor necrosis factor
R G Goodwin1, D Anderson, R Jerzy
1Immunex Corporation, Seattle, Washington 98101.
Abstract:
Clones encoding the type 1 (p80) and type 2 (p60) forms of the murine receptors for tumor necrosis factor (TNF) were isolated by cross-hybridization using probes derived from the cloned human TNF receptors. Each of the murine receptors shows strong sequence homology to the corresponding human receptor (approximately 65% amino acid identity) throughout the molecule but only modest homology, limited to ligand-binding domains, between themselves. The ligand-binding characteristics of the recombinant murine receptors mirror those of the human homologs: both receptor types bind TNF-alpha and -beta with multiple affinity classes, and the ligands cross-compete. Analysis of the murine transcripts encoding these receptors revealed the presence of RNAs for one or both forms of the receptors in all cells examined. It was also demonstrated that for both types of human TNF receptor, variably sized transcripts are observed in different cells. The murine cDNAs were further used to determine the chromosomal locations of the TNF receptor genes. They are not linked, in contrast to the ligands, and map to chromosomes 4 (type 1) and 6 (type 2).
Insights
Researchers isolated murine tumor necrosis factor (TNF) receptors, finding they mirror human receptor binding characteristics and map to different chromosomes. This advances understanding of TNF signaling pathways.
Area of Science:
- Immunology
- Molecular Biology
- Genetics
Background:
- Tumor necrosis factor (TNF) receptors mediate crucial cellular responses.
- Understanding the structure and function of TNF receptors is vital for immunology and disease research.
Purpose of the Study:
- To isolate and characterize murine tumor necrosis factor (TNF) receptors.
- To compare murine TNF receptors with their human counterparts.
- To determine the chromosomal locations of murine TNF receptor genes.
Main Methods:
- Cross-hybridization using probes from cloned human TNF receptors to isolate murine receptor clones.
- Sequence homology analysis between murine and human receptors.
- Ligand-binding assays with recombinant murine receptors.
- RNA analysis to study transcript expression.
- Chromosomal mapping of TNF receptor genes using murine cDNAs.
Main Results:
- Murine type 1 (p80) and type 2 (p60) TNF receptors were isolated, showing ~65% amino acid identity to human homologs.
- Recombinant murine receptors exhibited similar ligand-binding characteristics to human receptors, binding TNF-alpha and -beta with cross-competition.
- Transcripts for both receptor types were found in all examined murine cells.
- Murine TNF receptor genes were mapped to chromosomes 4 (type 1) and 6 (type 2), indicating they are not linked.
Conclusions:
- Murine TNF receptors share significant sequence homology and functional characteristics with human receptors.
- The differential chromosomal localization of murine TNF receptor genes provides insights into their genetic regulation.
- These findings contribute to a deeper understanding of TNF signaling pathways and their genetic basis.