Sequence variation in the Epstein-Barr virus latent membrane protein 1

Area of Science:

• Virology
• Molecular Biology
• Genetics

Background:

• Epstein-Barr virus (EBV) is a widespread human herpesvirus.
• Latent membrane protein 1 (LMP-1) is a key EBV-encoded oncoprotein.
• EBV exhibits genetic diversity, with distinct types and regional variations.

Purpose of the Study:

• To analyze the sequence of the LMP-1 gene in EBV isolates from different geographic regions.
• To identify sequence variations within LMP-1 that can distinguish between EBV types and strains.
• To compare LMP-1 sequences with prototype strains and investigate geographic-specific polymorphisms.

Main Methods:

• Sequencing of the LMP-1 gene from EBV isolates of type 1 and type 2.
• Analysis of restriction enzyme polymorphisms, specifically an XhoI REP.
• Comparison of nucleotide and amino acid sequences, focusing on amino and carboxy termini.

Main Results:

• A predominant XhoI restriction enzyme polymorphism (REP) in LMP-1 was identified in type 1 EBV from Southern China and type 2 EBV from Alaska.
• Consistent nucleotide variations were found in the amino terminus of LMP-1 in strains with the XhoI REP, present in both EBV types.
• Sequence variations, including repeat element differences and a specific deletion (amino acids 343-352), were observed in the carboxy terminus of LMP-1, with some variations correlating with EBV type and geographic origin.

Conclusions:

• EBV strains can be differentiated based on sequence variations within the LMP-1 gene.
• Unlike Epstein-Barr nuclear antigen sequences, LMP-1 sequences show significant similarity between EBV type 1 and type 2, despite regional variations.
• The identified LMP-1 sequence variations provide valuable markers for EBV strain typing and epidemiological studies.