The murine 2-5A synthetase locus: three distinct transcripts from two linked genes.

Area of Science:

• Molecular Biology
• Genetics
• Immunology

Background:

• The 2-5A synthetase (2-5A synthetase) enzyme plays a crucial role in the interferon-inducible antiviral response.
• Previous studies had identified cDNA clones for murine 2-5A synthetase, but the full genetic basis remained unclear.

Purpose of the Study:

• To characterize novel cDNAs encoding murine 2-5A synthetase.
• To map these cDNAs to the mouse genome and identify the relevant genes.
• To confirm the functional expression of these genes.

Main Methods:

• Cloning of complementary DNAs (cDNAs) encoding murine 2-5A synthetase.
• Southern blot analysis to examine gene organization.
• Transfection of cosmid DNA containing the genes into cultured cells.
• Interferon treatment and transcript analysis.

Main Results:

• Three related murine 2-5A synthetase transcripts (L1, L2, L3) were identified.
• The novel L1 cDNA encodes a protein with 70% amino acid conservation to L3.
• L2 recognizes a larger interferon-induced transcript.
• These transcripts map to a 40 kb genomic region containing two genes (ME12 and ME5/ME8) in a head-to-tail orientation.
• Transfected cells produced mature 2-5A synthetase transcripts upon interferon treatment.

Conclusions:

• The study successfully identified and characterized novel murine 2-5A synthetase transcripts.
• The genetic locus for these transcripts was localized to a specific region containing two 2-5A synthetase genes.
• Functional expression of these genes was confirmed in transfected cells, validating their role in interferon response.