Structural basis of the recognition of adeno-associated virus by the neurological system-related receptor carbonic anhydrase IV

• Published in: PLoS pathogens Vol. 20; no. 2; p. e1011953
• Main Authors: Zhang, Ran, Liu, Yixiao, Yu, Fengxi, Xu, Guangxue, Li, Lili, Li, Baobin, Lou, Zhiyong
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.02.2024; Public Library of Science (PLoS)
• Subjects: Algorithms; Amino acids; Animal models; Animals; Biology and Life Sciences; Blood-brain barrier; Blood-Brain Barrier - metabolism; Capsid - metabolism; Capsid Proteins - metabolism; Capsids; Carbonic anhydrase; Carbonic Anhydrase IV - analysis; Carbonic Anhydrase IV - metabolism; Carbonic anhydrases; Cellular structure; Central nervous system; Dependovirus - genetics; Directed evolution; Genetic Vectors; Hydrophobicity; Medicine and Health Sciences; Mice; Molecular modelling; Mutagenesis; Neurological system; Peptides; Physical Sciences; Proteins; Receptors; Recognition; Research and Analysis Methods; Symmetry; Variable region; Viruses; China
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1011953

Carbonic anhydrase IV (Car4) is a newly identified receptor that allows adeno-associated virus (AAV) 9P31 to cross the blood-brain barrier and achieve efficient infection in the central nervous system (CNS) in mouse models. However, the molecular mechanism by which engineered AAV capsids with 7-mer insertion in the variable region (VR) VIII recognize these novel cellular receptors is unknown. Here we report the cryo-EM structures of AAV9P31 and its complex with Mus musculus Car4 at atomic resolution by utilizing the block-based reconstruction (BBR) method. The structures demonstrated that Car4 binds to the protrusions at 3-fold axes of the capsid. The inserted 7-mer extends into a hydrophobic region near the catalytic center of Car4 to form stable interactions. Mutagenesis studies also identified the key residues in Car4 responsible for the AAV9P31 interaction. These findings provide new insights into the novel receptor recognition mechanism of AAV generated by directed evolution and highlight the application of the BBR method to studying the virus-receptor molecular mechanism.