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Rozzi SJ, Avdoshina V, Fields JA, Mocchetti I. Human immunodeficiency virus Tat impairs mitochondrial fission in neurons. Cell Death Discov 2018. [PMID: 29531805 PMCID: PMC5841280 DOI: 10.1038/s41420-017-0013-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Human immunodeficiency virus-1 (HIV) infection of the central nervous system promotes neuronal injury that culminates in HIV-associated neurocognitive disorders. Viral proteins, including transactivator of transcription (Tat), have emerged as leading candidates to explain HIV-mediated neurotoxicity, though the mechanisms remain unclear. Tat transgenic mice or neurons exposed to Tat, which show neuronal loss, exhibit smaller mitochondria as compared to controls. To provide an experimental clue as to which mechanisms are used by Tat to promote changes in mitochondrial morphology, rat cortical neurons were exposed to Tat (100 nM) for various time points. Within 30 min, Tat caused a significant reduction in mitochondrial membrane potential, a process that is regulated by fusion and fission. To further assess whether Tat changes these processes, fission and fusion proteins dynamin-related protein 1 (Drp1) and mitofusin-2 (Mfn2), respectively, were measured. We found that Drp1 levels increased beginning at 2 h after Tat exposure while Mfn2 remained unchanged. Moreover, increased levels of an active form of Drp1 were found to be present following Tat exposure. Furthermore, Drp1 and calcineurin inhibitors prevented Tat-mediated effects on mitochondria size. These findings indicate that mitochondrial fission is likely the leading factor in Tat-mediated alterations to mitochondrial morphology. This disruption in mitochondria homeostasis may contribute to the instability of the organelle and ultimately neuronal cell death following Tat exposure.
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Affiliation(s)
- Summer J Rozzi
- 1Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC USA.,2Laboratory of Preclinical Neurobiology, Department of Neuroscience, Georgetown University Medical Center, Washington, DC USA
| | - Valeria Avdoshina
- 2Laboratory of Preclinical Neurobiology, Department of Neuroscience, Georgetown University Medical Center, Washington, DC USA
| | - Jerel A Fields
- 3Department of Psychiatry, University of California San Diego, La Jolla, CA USA
| | - Italo Mocchetti
- 1Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC USA.,2Laboratory of Preclinical Neurobiology, Department of Neuroscience, Georgetown University Medical Center, Washington, DC USA
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Wayman WN, Chen L, Persons AL, Napier TC. Cortical consequences of HIV-1 Tat exposure in rats are enhanced by chronic cocaine. Curr HIV Res 2015; 13:80-7. [PMID: 25760043 DOI: 10.2174/0929867322666150311164504] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 01/22/2015] [Accepted: 02/09/2015] [Indexed: 01/25/2023]
Abstract
The life span of individuals that are sero-positive for human immunodeficiency virus (HIV) has greatly improved; however, complications involving the central nervous system (CNS) remain a concern. While HIV does not directly infect neurons, the proteins produced by the virus, including HIV transactivator of transcription (Tat), are released from infected glia; these proteins can be neurotoxic. This neurotoxicity is thought to mediate the pathology underlying HIVassociated neurological impairments. Cocaine abuse is common among HIV infected individuals, and this abuse augments HIV-associated neurological deficits. The brain regions and pathophysiological mechanisms that are dysregulated by both chronic cocaine and Tat are the focus of the current review.
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Affiliation(s)
- Wesley N Wayman
- Department of Pharmacology, Rush University Medical Center, 1735 W. Harrison Street, Cohn Research Building, Rm. 463, Chicago, IL 60612, USA.
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Fatin MF, Ruslinda AR, Md Arshad MK, Tee KK, Ayub RM, Hashim U, Kamarulzaman A, Gopinath SCB. HIV-1 Tat biosensor: Current development and trends for early detection strategies. Biosens Bioelectron 2015; 78:358-366. [PMID: 26655174 DOI: 10.1016/j.bios.2015.11.067] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/20/2015] [Accepted: 11/24/2015] [Indexed: 02/07/2023]
Abstract
Human immunodeficiency virus (HIV) has infected almost 35 million people worldwide. Various tests have been developed to detect the presence of HIV during the early stages of the disease in order to reduce the risk of transmission to other humans. The HIV-1 Tat protein is one of the proteins present in HIV that are released abundantly approximately 2-4 weeks after infection. In this review, we have outlined various strategies for detecting the Tat protein, which helps transcribe the virus and enhances replication. Detection strategies presented include immunoassays, biosensors and gene expression, which utilize antibodies or aptamers as common probes to sense the presence of Tat. Alternatively, measuring the levels of gene transcription is a direct method of analysing the HIV gene to confirm the presence of Tat. By detection of the Tat protein, virus transmission can be detected in high-risk individuals in the early stages of the disease to reduce the risk of an HIV pandemic.
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Affiliation(s)
- M F Fatin
- Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, Kangar, 01000 Perlis, Malaysia
| | - A R Ruslinda
- Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, Kangar, 01000 Perlis, Malaysia.
| | - M K Md Arshad
- Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, Kangar, 01000 Perlis, Malaysia
| | - K K Tee
- Center of Excellence for Research in AIDS (CERiA), Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - R M Ayub
- Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, Kangar, 01000 Perlis, Malaysia
| | - U Hashim
- Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, Kangar, 01000 Perlis, Malaysia
| | - A Kamarulzaman
- Center of Excellence for Research in AIDS (CERiA), Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Subash C B Gopinath
- Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, Kangar, 01000 Perlis, Malaysia
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Vlach J, Samal AB, Saad JS. Solution structure of calmodulin bound to the binding domain of the HIV-1 matrix protein. J Biol Chem 2014; 289:8697-705. [PMID: 24500712 DOI: 10.1074/jbc.m113.543694] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Subcellular distribution of calmodulin (CaM) in human immunodeficiency virus type-1 (HIV-1)-infected cells is distinct from that observed in uninfected cells. CaM co-localizes and interacts with the HIV-1 Gag protein in the cytosol of infected cells. Although it has been shown that binding of Gag to CaM is mediated by the matrix (MA) domain, the structural details of this interaction are not known. We have recently shown that binding of CaM to MA induces a conformational change that triggers myristate exposure, and that the CaM-binding domain of MA is confined to a region spanning residues 8-43 (MA-(8-43)). Here, we present the NMR structure of CaM bound to MA-(8-43). Our data revealed that MA-(8-43), which contains a novel CaM-binding motif, binds to CaM in an antiparallel mode with the N-terminal helix (α1) anchored to the CaM C-terminal lobe, and the C-terminal helix (α2) of MA-(8-43) bound to the N-terminal lobe of CaM. The CaM protein preserves a semiextended conformation. Binding of MA-(8-43) to CaM is mediated by numerous hydrophobic interactions and stabilized by favorable electrostatic contacts. Our structural data are consistent with the findings that CaM induces unfolding of the MA protein to have access to helices α1 and α2. It is noteworthy that several MA residues involved in CaM binding have been previously implicated in membrane binding, envelope incorporation, and particle production. The present findings may ultimately help in identification of the functional role of CaM in HIV-1 replication.
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Affiliation(s)
- Jiri Vlach
- From the Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Nakahara KS, Masuta C, Yamada S, Shimura H, Kashihara Y, Wada TS, Meguro A, Goto K, Tadamura K, Sueda K, Sekiguchi T, Shao J, Itchoda N, Matsumura T, Igarashi M, Ito K, Carthew RW, Uyeda I. Tobacco calmodulin-like protein provides secondary defense by binding to and directing degradation of virus RNA silencing suppressors. Proc Natl Acad Sci U S A 2012; 109:10113-8. [PMID: 22665793 PMCID: PMC3382489 DOI: 10.1073/pnas.1201628109] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
RNA silencing (RNAi) induced by virus-derived double-stranded RNA (dsRNA), which is in a sense regarded as a pathogen-associated molecular pattern (PAMP) of viruses, is a general plant defense mechanism. To counteract this defense, plant viruses express RNA silencing suppressors (RSSs), many of which bind to dsRNA and attenuate RNAi. We showed that the tobacco calmodulin-like protein, rgs-CaM, counterattacked viral RSSs by binding to their dsRNA-binding domains and sequestering them from inhibiting RNAi. Autophagy-like protein degradation seemed to operate to degrade RSSs with the sacrifice of rgs-CaM. These RSSs could thus be regarded as secondary viral PAMPs. This study uncovered a unique defense system in which an rgs-CaM-mediated countermeasure against viral RSSs enhanced host antiviral RNAi in tobacco.
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Affiliation(s)
- Kenji S. Nakahara
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Chikara Masuta
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Syouta Yamada
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Hanako Shimura
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Yukiko Kashihara
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Tomoko S. Wada
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Ayano Meguro
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Kazunori Goto
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Kazuki Tadamura
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Kae Sueda
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Toru Sekiguchi
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Jun Shao
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Noriko Itchoda
- Plant Breeding and Production Division, Agricultural Research Institute, Hokuren Federation of Agricultural Cooperatives, Naganuma, Hokkaido 069-1317, Japan
| | - Takeshi Matsumura
- Plant Molecular Technology Research Group, Research Institute of Genome-Based Biofactory, National Institute of Advanced Industrial Science and Technology, Sapporo 062-8517, Japan
| | - Manabu Igarashi
- Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, 001-0020, Japan; and
| | - Kimihito Ito
- Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, 001-0020, Japan; and
| | - Richard W. Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Ichiro Uyeda
- Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
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