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Nucleotide sequence of human monocyte interleukin 1 precursor cDNA
Abstract:
Interleukin 1 (IL-1) is a protein with several biological activities regulating host defense and immune responses. We report here the isolation of human IL-1 cDNA. It encodes a precursor polypeptide of 269 amino acids (30,747 Mr). mRNA isolated by hybridization to this cDNA was translated in a reticulocyte cell-free system, yielding immunoprecipitable IL-1. Furthermore, this hybrid-selected mRNA was injected into Xenopus laevis oocytes, which subsequently secreted biologically active IL-1. The cDNA nucleotide sequence suggests that IL-1 is initially translated as a precursor molecule that is subsequently processed into the 15,000-20,000 Mr protein usually associated with IL-1 activity.
Insights
Researchers isolated human Interleukin 1 (IL-1) cDNA, revealing it encodes a precursor protein. This precursor is processed into the active IL-1 form, crucial for immune responses.
Area of Science:
- Immunology
- Molecular Biology
- Genetics
Background:
- Interleukin 1 (IL-1) is a key protein involved in host defense and immune responses.
- Understanding IL-1's molecular basis is crucial for immunology research.
Purpose of the Study:
- To isolate and characterize the human Interleukin 1 (IL-1) cDNA.
- To elucidate the precursor form and processing of IL-1.
Main Methods:
- Isolation of human IL-1 cDNA using hybridization techniques.
- In vitro translation of isolated mRNA in a reticulocyte system.
- Expression of hybrid-selected mRNA in Xenopus laevis oocytes.
Main Results:
- Successfully isolated human IL-1 cDNA encoding a 269 amino acid precursor (30,747 Mr).
- Cell-free translation yielded immunoprecipitable IL-1.
- Oocyte injection led to the secretion of biologically active IL-1.
- Sequence analysis indicated IL-1 is initially translated as a precursor and then processed.
Conclusions:
- The study provides the cDNA sequence for human IL-1.
- Evidence suggests IL-1 is synthesized as a larger precursor molecule and subsequently processed to its active form.
- This finding advances the understanding of IL-1's molecular regulation in immune processes.