Tumorvirus-specific Vaccination Strategies

Ubiquitin E3 ligases: Restriction factors for Adeno-associated virus entry?

Robin Njenga, PhD student

© dkfz.de

Introduction: Entry of AAV

© dkfz.de

Adeno associated virus (AAV) is a small, single stranded DNA virus from the family of Parvoviridae.  AAV infects dividing and non-dividing cells and has a broad tissue tropism which makes it a very promising candidate for gene therapy. However it has sub-optimal transduction efficiency due to its interaction with various host and restriction factors. AAV2 (The most well studied serotype) has also been found to be targeted by ubiquitination for proteasomal degradation.

Interaction of E3 ligase and VP

© dkfz.de

Adeno associated virus (AAV) is a small, single stranded DNA virus from the family of Parvoviridae.  AAV infects dividing and non-dividing cells and has a broad tissue tropism which makes it a very promising candidate for gene therapy. However it has sub-optimal transduction efficiency due to its interaction with various host and restriction factors. AAV2 (The most well studied serotype) has also been found to be targeted by ubiquitination for proteasomal degradation.

The cullin-E3- Ubiquitin ligase complex is responsible for the targeting of proteins by ubiquitination and subsequent proteasomal degradation. TAP tag experiments performed previously in the lab found that an adaptor protein in the complex interacts with VP1 (an AAV capsid protein). Also co-transfection and immunofluorescence shows the co-localization of both proteins in distinct speckles.

Knockdown of the adaptor protein results in a 6-fold increase in AAV transduction efficiency. Therefore we propose a possible mechanism whereby upon AAV infection, the viral capsid interacts with E3-ubiquitin ligase complex, which facilitates ubiquination and subsequent degradation.

The aim of this project is to characterize this interaction by localizing the adaptor binding site on AAV capsid proteins and determining what the consequence of this interaction is.

to top
powered by webEdition CMS