The Assembly-Activating Protein Promotes Capsid Assembly of Different Adeno-Associated Virus Serotypes
- 1 December 2011
- journal article
- Published by American Society for Microbiology in Journal of Virology
- Vol. 85 (23), 12686-12697
- https://doi.org/10.1128/jvi.05359-11
Abstract
Adeno-associated virus type 2 (AAV2) capsid assembly requires the expression of a virally encoded assembly-activating protein (AAP). By providing AAP together with the capsid protein VP3, capsids are formed that are composed of VP3 only. Electron cryomicroscopy analysis of assembled VP3-only capsids revealed all characteristics of the wild-type AAV2 capsids. However, in contrast to capsids assembled from VP1, VP2, and VP3, the pores of VP3-only capsids were more restricted at the inside of the 5-fold symmetry axes, and globules could not be detected below the 2-fold symmetry axes. By comparing the capsid assembly of several AAV serotypes with AAP protein from AAV2 (AAP-2), we show that AAP-2 is able to efficiently stimulate capsid formation of VP3 derived from several serotypes, as demonstrated for AAV1, AAV2, AAV8, and AAV9. Capsid formation, by coexpressing AAV1-, AAV2-, or AAV5-VP3 with AAP-1, AAP-2, or AAP-5 revealed the ability of AAP-1 and AAP-2 to complement each other in AAV1 and AAV2 assembly, whereas for AAV5 assembly more specific conditions are required. Sequence alignment of predicted AAP proteins from the known AAV serotypes indicates a high degree of homology of all serotypes to AAP-2 with some divergence for AAP-4, AAP-5, AAP-11, and AAP-12. Immunolocalization of assembled capsids from different serotypes confirmed the preferred nucleolar localization of capsids, as observed for AAV2; however, AAV8 and AAV9 capsids could also be detected throughout the nucleus. Taken together, the data show that AAV capsid assembly of different AAV serotypes also requires the assistance of AAP proteins.Keywords
This publication has 46 references indexed in Scilit:
- A viral assembly factor promotes AAV2 capsid formation in the nucleolusProceedings of the National Academy of Sciences, 2010
- SPIDER image processing for single-particle reconstruction of biological macromolecules from electron micrographsNature Protocols, 2008
- Adeno-Associated Virus Type 12 (AAV12): a Novel AAV Serotype with Sialic Acid- and Heparan Sulfate Proteoglycan-Independent Transduction ActivityJournal of Virology, 2008
- Distance-Dependent Processing of Adeno-Associated Virus Type 5 RNA Is Controlled by 5′ Exon DefinitionJournal of Virology, 2007
- Adeno-associated virus interactions with B23/Nucleophosmin: Identification of sub-nucleolar virion regionsVirology, 2007
- UCSF Chimera?A visualization system for exploratory research and analysisJournal of Computational Chemistry, 2004
- Alternative Polyadenylation of Adeno-Associated Virus Type 5 RNA within an Internal Intron Is Governed by both a Downstream Element within the Intron 3′ Splice Acceptor and an Element Upstream of the P41 Initiation SiteJournal of Virology, 2004
- Characterization of the Transcription Profile of Adeno-Associated Virus Type 5 Reveals a Number of Unique Features Compared to Previously Characterized Adeno-Associated VirusesJournal of Virology, 2002
- EMAN: Semiautomated Software for High-Resolution Single-Particle ReconstructionsJournal of Structural Biology, 1999
- Determination of the fold of the core protein of hepatitis B virus by electron cryomicroscopyNature, 1997