AAV2-U6-miRNA-GFP

Adeno-associated virus (AAV) is a non-pathogenic member of the genus Dependovirus in the family Parvoviridae. A large number of AAV serotypes have been described and studied for gene delivery applications. They differ in receptor binding, host cell tropism, and antigenic properties. To date, most gene therapy applications have used AAV serotype 2 (AAV2), which is currently the subject of clinical trials for the correction of hemophilia, cystic fibrosis, and other diseases. The AAV capsid consists of a T = 1 icosahedral symmetry with a diameter of approximately 260 Å, encapsulating a 4.7 kb ssDNA genome. The genome has two open reading frames (ORFs), rep and cap, encoding replication and capsid proteins, respectively. The 60-subunit viral capsid is composed of three viral proteins (VP), of which the 62 kDa VP3 protein accounts for approximately 90% of the structure. The minor capsid proteins VP1 (87 kDa) and VP2 (73 kDa) share a common C-terminal amino acid sequence with VP3 but have an N-terminal extension. The N-terminal sequence unique to VP1 confers phospholipase A2 (PLA2) activity, which is essential for infectivity as well as nuclear localization signaling at the step between endocytosis and nuclear entry. In addition to protecting the ssDNA genome, the AAV capsid mediates several steps in the viral life cycle, including primary and secondary receptor recognition and antigenicity.