Noncoding control region of naturally occurring BK virus variants: sequence comparison and functional analysis

Area of Science:

• Virology
• Molecular Biology
• Oncology

Background:

• The human polyomavirus BK (BKV) possesses oncogenic potential, but its role in natural tumorigenesis is unclear.
• BKV's genome includes coding regions for early and late genes, separated by a noncoding control region (NCCR) that regulates transcription.
• NCCR sequences vary significantly among BKV isolates due to deletions, duplications, and rearrangements.

Purpose of the Study:

• To review naturally occurring BKV NCCR variants isolated directly from human samples.
• To compare and analyze the sequences of different NCCRs for transcription factor binding sites.
• To discuss the biological significance of NCCR variation in relation to viral properties and oncogenic potential.

Main Methods:

• Review of published studies on naturally occurring BKV NCCR variants.
• Sequence comparison and analysis of identified NCCRs.
• Identification of proven and putative cellular transcription factor binding sites within NCCRs.

Main Results:

• Significant sequence variation exists in naturally occurring BKV NCCRs, unlike the conserved protein-coding regions.
• NCCR anatomy correlates with transcriptional activity, host cell tropism, permissivity, and oncogenic potential.
• PCR technology enables the study of BKV NCCR variation without prior virus propagation in cell culture.

Conclusions:

• Naturally occurring BKV NCCR variation is a key factor influencing viral behavior and oncogenic potential.
• Analysis of NCCR sequences provides insights into the mechanisms of BKV-associated tumorigenesis.
• BKV NCCRs serve as valuable models for studying mammalian promoter/enhancer functions and transcription factor interactions.