Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.

BACKGROUND: The majority of viruses enter host cells via endocytosis. Current knowledge of viral entry pathways is largely based upon infectivity measurements following genetic and/or pharmacological interventions that disrupt vesicular trafficking and maturation. Imaging of single virus entry in li...

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Main Authors: Padilla-Parra, S, Marin, M, Kondo, N, Melikyan, G
Format: Journal article
Language:English
Published: BioMed Central 2014
Subjects:
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author Padilla-Parra, S
Marin, M
Kondo, N
Melikyan, G
author_facet Padilla-Parra, S
Marin, M
Kondo, N
Melikyan, G
author_sort Padilla-Parra, S
collection OXFORD
description BACKGROUND: The majority of viruses enter host cells via endocytosis. Current knowledge of viral entry pathways is largely based upon infectivity measurements following genetic and/or pharmacological interventions that disrupt vesicular trafficking and maturation. Imaging of single virus entry in living cells provides a powerful means to delineate viral trafficking pathways and entry sites under physiological conditions. RESULTS: Here, we visualized single avian retrovirus co-trafficking with markers for early (Rab5) and late (Rab7) endosomes, acidification of endosomal lumen and the resulting viral fusion measured by the viral content release into the cytoplasm. Virus-carrying vesicles either merged with the existing Rab5-positive early endosomes or slowly accumulated Rab5. The Rab5 recruitment to virus-carrying endosomes correlated with acidification of their lumen. Viral fusion occurred either in early (Rab5-positive) or intermediate (Rab5- and Rab7-positive) compartments. Interestingly, different isoforms of the cognate receptor directed virus entry from distinct endosomes. In cells expressing the transmembrane receptor, viruses preferentially entered and fused with slowly maturing early endosomes prior to accumulation of Rab7. By comparison, in cells expressing the GPI-anchored receptor, viruses entered both slowly and quickly maturing endosomes and fused with early (Rab5-positive) and intermediate (Rab5- and Rab7-positive) compartments. CONCLUSIONS: Since the rate of low pH-triggered fusion was independent of the receptor isoform, we concluded that the sites of virus entry are determined by the kinetic competition between endosome maturation and viral fusion. Our findings demonstrate the ability of this retrovirus to enter cells via alternative endocytic pathways and establish infection by releasing its content from distinct endosomal compartments.
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spelling oxford-uuid:32adc744-a344-403f-92bd-90dcac412bf42022-03-26T13:15:36ZPinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:32adc744-a344-403f-92bd-90dcac412bf4VirusesEnglishSymplectic Elements at OxfordBioMed Central2014Padilla-Parra, SMarin, MKondo, NMelikyan, GBACKGROUND: The majority of viruses enter host cells via endocytosis. Current knowledge of viral entry pathways is largely based upon infectivity measurements following genetic and/or pharmacological interventions that disrupt vesicular trafficking and maturation. Imaging of single virus entry in living cells provides a powerful means to delineate viral trafficking pathways and entry sites under physiological conditions. RESULTS: Here, we visualized single avian retrovirus co-trafficking with markers for early (Rab5) and late (Rab7) endosomes, acidification of endosomal lumen and the resulting viral fusion measured by the viral content release into the cytoplasm. Virus-carrying vesicles either merged with the existing Rab5-positive early endosomes or slowly accumulated Rab5. The Rab5 recruitment to virus-carrying endosomes correlated with acidification of their lumen. Viral fusion occurred either in early (Rab5-positive) or intermediate (Rab5- and Rab7-positive) compartments. Interestingly, different isoforms of the cognate receptor directed virus entry from distinct endosomes. In cells expressing the transmembrane receptor, viruses preferentially entered and fused with slowly maturing early endosomes prior to accumulation of Rab7. By comparison, in cells expressing the GPI-anchored receptor, viruses entered both slowly and quickly maturing endosomes and fused with early (Rab5-positive) and intermediate (Rab5- and Rab7-positive) compartments. CONCLUSIONS: Since the rate of low pH-triggered fusion was independent of the receptor isoform, we concluded that the sites of virus entry are determined by the kinetic competition between endosome maturation and viral fusion. Our findings demonstrate the ability of this retrovirus to enter cells via alternative endocytic pathways and establish infection by releasing its content from distinct endosomal compartments.
spellingShingle Viruses
Padilla-Parra, S
Marin, M
Kondo, N
Melikyan, G
Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.
title Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.
title_full Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.
title_fullStr Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.
title_full_unstemmed Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.
title_short Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.
title_sort pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging
topic Viruses
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