Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry

<p>Abstract</p> <p>Human papillomaviruses (HPV) infect stratified epithelia and restrict expression of late capsid genes to highly differentiated cells. In order to begin to understand the processes regulating HPV 31 infection we examined the synthesis of the HPV 31 capsid proteins...

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Main Authors: Hindmarsh Patrick L, Laimins Laimonis A
Format: Article
Language:English
Published: BMC 2007-02-01
Series:Virology Journal
Online Access:http://www.virologyj.com/content/4/1/19
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author Hindmarsh Patrick L
Laimins Laimonis A
author_facet Hindmarsh Patrick L
Laimins Laimonis A
author_sort Hindmarsh Patrick L
collection DOAJ
description <p>Abstract</p> <p>Human papillomaviruses (HPV) infect stratified epithelia and restrict expression of late capsid genes to highly differentiated cells. In order to begin to understand the processes regulating HPV 31 infection we examined the synthesis of the HPV 31 capsid proteins, L1 and L2, using heterologous expression systems. Similar to studies in HPV 16, expression of wild type HPV 31 L1 and L2 from heterologous promoters resulted in very low levels of synthesis. In contrast, modification of the codons in the capsid genes to ones more commonly used in cellular genes resulted in high-level synthesis. Through the use of chimeric proteins that fused fragments of wild type L1 to Green Fluorescent Protein (GFP) coding sequences, a short region was identified that was sufficient to inhibit high level synthesis and similar elements were detected in L2. One element was localized to the 3' end of the L1 gene while a series of elements were localized at the 3' end of the L2 coding sequences. These observations are most consistent with negative RNA regulatory elements controlling the levels of L1 and L2 synthesis that are distinct from those identified in HPV 16. Expression vectors for the codon modified HPV 31 capsid proteins were then transfected together with GFP reporter plasmids to generate HPV 31 pseudoviruses. Infection of cells with HPV 31 pseudoviruses in the presence of the inhibitors, chlorpromazine, nystatin or methyl-beta-cyclodextrin, demonstrated that HPV 31, like HPV 16, enters human and monkey cells through a clathrin-mediated pathway rather than through caveolae as previously reported. This suggests that high-risk HPV types may enter cells through common mechanisms.</p>
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spelling doaj.art-148117762d9440808d00408577968ef92022-12-22T03:26:07ZengBMCVirology Journal1743-422X2007-02-01411910.1186/1743-422X-4-19Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entryHindmarsh Patrick LLaimins Laimonis A<p>Abstract</p> <p>Human papillomaviruses (HPV) infect stratified epithelia and restrict expression of late capsid genes to highly differentiated cells. In order to begin to understand the processes regulating HPV 31 infection we examined the synthesis of the HPV 31 capsid proteins, L1 and L2, using heterologous expression systems. Similar to studies in HPV 16, expression of wild type HPV 31 L1 and L2 from heterologous promoters resulted in very low levels of synthesis. In contrast, modification of the codons in the capsid genes to ones more commonly used in cellular genes resulted in high-level synthesis. Through the use of chimeric proteins that fused fragments of wild type L1 to Green Fluorescent Protein (GFP) coding sequences, a short region was identified that was sufficient to inhibit high level synthesis and similar elements were detected in L2. One element was localized to the 3' end of the L1 gene while a series of elements were localized at the 3' end of the L2 coding sequences. These observations are most consistent with negative RNA regulatory elements controlling the levels of L1 and L2 synthesis that are distinct from those identified in HPV 16. Expression vectors for the codon modified HPV 31 capsid proteins were then transfected together with GFP reporter plasmids to generate HPV 31 pseudoviruses. Infection of cells with HPV 31 pseudoviruses in the presence of the inhibitors, chlorpromazine, nystatin or methyl-beta-cyclodextrin, demonstrated that HPV 31, like HPV 16, enters human and monkey cells through a clathrin-mediated pathway rather than through caveolae as previously reported. This suggests that high-risk HPV types may enter cells through common mechanisms.</p>http://www.virologyj.com/content/4/1/19
spellingShingle Hindmarsh Patrick L
Laimins Laimonis A
Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry
Virology Journal
title Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry
title_full Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry
title_fullStr Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry
title_full_unstemmed Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry
title_short Mechanisms regulating expression of the HPV 31 L1 and L2 capsid proteins and pseudovirion entry
title_sort mechanisms regulating expression of the hpv 31 l1 and l2 capsid proteins and pseudovirion entry
url http://www.virologyj.com/content/4/1/19
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