Related Experiment Video
Updated: Nov 5, 2025

Merkel Cell Polyomavirus Infection and Detection
Published on: February 7, 2019
Characterization of ALTO-encoding circular RNAs expressed by Merkel cell polyomavirus and trichodysplasia spinulosa
Rong Yang1, Eunice E Lee1, Jiwoong Kim2
1Department of Dermatology, UT Southwestern Medical Center, Dallas, Texas, United States of America.
Abstract:
Circular RNAs (circRNAs) are a conserved class of RNAs with diverse functions, including serving as messenger RNAs that are translated into peptides. Here we describe circular RNAs generated by human polyomaviruses (HPyVs), some of which encode variants of the previously described alternative large T antigen open reading frame (ALTO) protein. Circular ALTO RNAs (circALTOs) can be detected in virus positive Merkel cell carcinoma (VP-MCC) cell lines and tumor samples. CircALTOs are stable, predominantly located in the cytoplasm, and N6-methyladenosine (m6A) modified. The translation of MCPyV circALTOs into ALTO protein is negatively regulated by MCPyV-generated miRNAs in cultured cells. MCPyV ALTO expression increases transcription from some recombinant promoters in vitro and upregulates the expression of multiple genes previously implicated in MCPyV pathogenesis. MCPyV circALTOs are enriched in exosomes derived from VP-MCC lines and circALTO-transfected 293T cells, and purified exosomes can mediate ALTO expression and transcriptional activation in MCPyV-negative cells. The related trichodysplasia spinulosa polyomavirus (TSPyV) also expresses a circALTO that can be detected in infected tissues and produces ALTO protein in cultured cells. Thus, human polyomavirus circRNAs are expressed in human tumors and infected tissues and express proteins that have the potential to modulate the infectious and tumorigenic properties of these viruses.
More Related Videos
11:54Measurement of BK-polyomavirus Non-Coding Control Region Driven Transcriptional Activity Via Flow Cytometry
Published on: July 13, 2019
06:21Quantitative Fluorescence In Situ Hybridization FISH and Immunofluorescence IF of Specific Gene Products in KSHV-Infected Cells
Published on: August 27, 2019
Related Concept Videos
Rous Sarcoma Virus (RSV) and Cancer
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...
Non-LTR Retrotransposons
Mechanisms of Retrovirus-induced Cancers
Leaky Scanning
Subviral Agents