1
|
Ismail AM, Saha A, Lee JS, Painter DF, Chen Y, Singh G, Condezo GN, Chodosh J, San Martín C, Rajaiya J. RANBP2 and USP9x regulate nuclear import of adenovirus minor coat protein IIIa. PLoS Pathog 2022; 18:e1010588. [PMID: 35709296 PMCID: PMC9242475 DOI: 10.1371/journal.ppat.1010588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 06/29/2022] [Accepted: 05/11/2022] [Indexed: 11/30/2022] Open
Abstract
As intracellular parasites, viruses exploit cellular proteins at every stage of infection. Adenovirus outbreaks are associated with severe acute respiratory illnesses and conjunctivitis, with no specific antiviral therapy available. An adenoviral vaccine based on human adenovirus species D (HAdV-D) is currently in use for COVID-19. Herein, we investigate host interactions of HAdV-D type 37 (HAdV-D37) protein IIIa (pIIIa), identified by affinity purification and mass spectrometry (AP-MS) screens. We demonstrate that viral pIIIa interacts with ubiquitin-specific protease 9x (USP9x) and Ran-binding protein 2 (RANBP2). USP9x binding did not invoke its signature deubiquitination function but rather deregulated pIIIa-RANBP2 interactions. In USP9x-knockout cells, viral genome replication and viral protein expression increased compared to wild type cells, supporting a host-favored mechanism for USP9x. Conversely, RANBP2-knock down reduced pIIIa transport to the nucleus, viral genome replication, and viral protein expression. Also, RANBP2-siRNA pretreated cells appeared to contain fewer mature viral particles. Transmission electron microscopy of USP9x-siRNA pretreated, virus-infected cells revealed larger than typical paracrystalline viral arrays. RANBP2-siRNA pretreatment led to the accumulation of defective assembly products at an early maturation stage. CRM1 nuclear export blockade by leptomycin B led to the retention of pIIIa within cell nuclei and hindered pIIIa-RANBP2 interactions. In-vitro binding analyses indicated that USP9x and RANBP2 bind to C-terminus of pIIIa amino acids 386–563 and 386–510, respectively. Surface plasmon resonance testing showed direct pIIIa interaction with recombinant USP9x and RANBP2 proteins, without competition. Using an alternative and genetically disparate adenovirus type (HAdV-C5), we show that the demonstrated pIIIa interaction is also important for a severe respiratory pathogen. Together, our results suggest that pIIIa hijacks RANBP2 for nuclear import and subsequent virion assembly. USP9x counteracts this interaction and negatively regulates virion synthesis. This analysis extends the scope of known adenovirus-host interactions and has potential implications in designing new antiviral therapeutics. The compact genomes of viruses must code for proteins with multiple functions, including those that assist with cell entry, replication, and escape from the host immune defenses. Viruses succeed in every stage of this process by hijacking critical cellular proteins for their propagation. Hence, identifying virus-host protein interactions may permit identifying therapeutic applications that restrict viral processes. Human adenovirus structural proteins link together to produce infectious virions. Protein IIIa is required to assemble fully packaged virions, but its interactions with host factors are unknown. Here, we identify novel host protein interactions of pIIIa with cellular RANBP2 and USP9x. We demonstrate that by interacting with cellular RANBP2, viral pIIIa gains entry to the nucleus for subsequent virion assembly and replication. Reduced RANBP2 expression inhibited pIIIa entry into the nucleus, minimized viral replication and viral protein expression, and led to accumulation of defective assembly products in the infected cells. As a defense against viral infection, USP9x reduces the interaction between pIIIa and RANBP2, resulting in decreased viral propagation. We also show that the identified pIIIa-host interactions are crucial in two disparate HAdV types with diverse disease implications.
Collapse
Affiliation(s)
- Ashrafali M. Ismail
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Amrita Saha
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ji S. Lee
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David F. Painter
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yinghua Chen
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Gurdeep Singh
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gabriela N. Condezo
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Madrid, Spain
| | - James Chodosh
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Carmen San Martín
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Madrid, Spain
| | - Jaya Rajaiya
- Department of Ophthalmology, Viral Pathogenesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
2
|
Nemerow GR, Stewart PL, Reddy VS. Structure of human adenovirus. Curr Opin Virol 2012; 2:115-21. [PMID: 22482707 DOI: 10.1016/j.coviro.2011.12.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 12/23/2011] [Indexed: 10/14/2022]
Abstract
A detailed structural analysis of the entire human adenovirus capsid has been stymied by the complexity and size of this 150 MDa macromolecular complex. Over the past 10 years, the steady improvements in viral genome manipulation concomitant with advances in crystallographic techniques and data processing software has allowed structure determination of this virus by X-ray diffraction at 3.5 Å resolution. The virus structure revealed the location, folds, and interactions of major and minor (cement proteins) on the inner and outer capsid surface. This new structural information sheds further light on the process of adenovirus capsid assembly and virus-host cell interactions.
Collapse
Affiliation(s)
- Glen R Nemerow
- The Scripps Research Institute, La Jolla, CA 92037, United States.
| | | | | |
Collapse
|
3
|
Molin M, Bouakaz L, Berenjian S, Akusjärvi G. Unscheduled expression of capsid protein IIIa results in defects in adenovirus major late mRNA and protein expression. Virus Res 2002; 83:197-206. [PMID: 11864752 DOI: 10.1016/s0168-1702(01)00443-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adenovirus gene expression is to a large extent regulated at the level of alternative RNA splicing. For example, in the major late region 1 (L1) unit, a common 5' splice site can be joined to two alternative 3' splice sites, resulting in the formation of the so-called 52,55K (proximal 3' splice site) or the IIIa (distal 3' splice site) mRNAs. Whereas, the 52,55K mRNA is expressed both early and late during infection, the IIIa mRNA is strictly confined to the late phase of the infectious cycle. We have previously shown that IIIa mRNA splicing is subjected to a tight viral control of IIIa 3 splice site usage. In an attempt to determine why adenovirus uses elaborate mechanisms to confine IIIa mRNA production to the late phase of infection, we characterized the phenotype of a recombinant adenovirus expressing the IIIa protein from an inducible tetracycline regulated gene cassette. The results show that expression of the IIIa protein during the early phase of infection results in a significant reduction in late viral protein synthesis and a moderate block to viral DNA replication. Interestingly, unscheduled IIIa protein expression resulted in a perturbation of the accumulation of alternatively spliced L1 mRNAs. Thus, 52,55K mRNA accumulation was inhibited while no effects on endogenous IIIa mRNA expression was detected.
Collapse
Affiliation(s)
- Magnus Molin
- Department of Medical Biochemistry and Microbiology, BMC, Uppsala University, Box 582, SE-751 23 Uppsala, Sweden
| | | | | | | |
Collapse
|