Mutational analysis of the rotavirus NSP4 enterotoxic domain that binds to caveolin-1

Ball, Joseph A.; Schroeder, Megan E.; Williams, Cecelia V.; Schroeder, Friedhelm; Parr, Rebecca D.

doi:10.1186/1743-422x-10-336

Cited by 14 publications

(8 citation statements)

References 51 publications

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“…PLA signals between NS1 and each of the CCC proteins in infected mosquito cells were demonstrated to be similar to those observed between CAV-1 and FKBP52, Cy40, and CyA (10). CAV-1-dependent secretion has been reported for nonviral proteins, such as Kallikrein 6 in colon cancer cells and Cyr61 in lung cells (33,34), as well as nonstructural viral proteins, such as rotavirus NSP4 (35,36).…”

Section: Discussionsupporting

confidence: 59%

The Dengue Virus Nonstructural Protein 1 (NS1) Is Secreted from Mosquito Cells in Association with the Intracellular Cholesterol Transporter Chaperone Caveolin Complex

Rosales

Ludert

2019

J Virol

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Dengue virus (DENV) is a mosquito-borne virus of the family Flaviviridae. The RNA viral genome encodes three structural and seven nonstructural proteins. Nonstructural protein 1 (NS1) is a multifunctional protein actively secreted in vertebrate and mosquito cells during infection. In mosquito cells, NS1 is secreted in a caveolin-1-dependent manner by an unconventional route. The caveolin chaperone complex (CCC) is a cytoplasmic complex formed by caveolin-1 and the chaperones FKBP52, Cy40, and CyA and is responsible for the cholesterol traffic inside the cell. In this work, we demonstrate that in mosquito cells, but not in vertebrate cells, NS1 associates with and relies on the CCC for secretion. Treatment of mosquito cells with classic secretion inhibitors, such as brefeldin A, Golgicide A, and Fli-06, showed no effect on NS1 secretion but significant reductions in recombinant luciferase secretion and virion release. Silencing the expression of CAV-1 or FKBP52 with short interfering RNAs or the inhibition of CyA by cyclosporine resulted in significant decrease in NS1 secretion, again without affecting virion release. Colocalization, coimmunoprecipitation, and proximity ligation assays indicated that NS1 colocalizes and interacts with all proteins of the CCC. In addition, CAV-1 and FKBP52 expression was found augmented in DENV-infected cells. Results obtained with Zika virus-infected cells suggest that in mosquito cells, ZIKV NS1 follows the same secretory pathway as that observed for DENV NS1. These results uncover important differences in the dengue virus-cell interactions between the vertebrate host and the mosquito vector as well as novel functions for the chaperone caveolin complex. IMPORTANCE The dengue virus protein NS1 is secreted efficiently from both infected vertebrate and mosquito cells. Previously, our group reported that NS1 secretion in mosquito cells follows an unconventional secretion pathway dependent on caveolin-1. In this work, we demonstrate that in mosquito cells, but not in vertebrate cells, NS1 secretion takes place in association with the chaperone caveolin complex, a complex formed by caveolin-1 and the chaperones FKBP52, CyA, and Cy40, which are in charge of cholesterol transport inside the cell. Results obtained with ZIKV-infected mosquito cells suggest that ZIKV NS1 is released following an unconventional secretory route in association with the chaperone caveolin complex. These results uncover important differences in the virus-cell interactions between the vertebrate host and the mosquito vector, as well as novel functions for the chaperone caveolin complex. Moreover, manipulation of the NS1 secretory route may prove a valuable strategy to combat these two mosquito-borne diseases. Volume 93 Issue 4 e01985-18 jvi.asm.org 2 on March 18, 2020 by guest http://jvi.asm.org/ Downloaded from plasma membrane, mediated by the CCC, to reach the extracellular space. In addition, data are presented suggesting that a similar pathway is used for the secretion of Zika virus NS1 protein in infected m...

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Section: Discussionsupporting

confidence: 59%

The Dengue Virus Nonstructural Protein 1 (NS1) Is Secreted from Mosquito Cells in Association with the Intracellular Cholesterol Transporter Chaperone Caveolin Complex

Rosales

Ludert

2019

J Virol

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“…Proteins of a number of viruses have been shown to have properties lytic or toxic for host cell membranes, but only one group of viruses, the rotaviruses, has been shown to produce an independent, non-structural protein that serves as a cytotoxin or entertoxin, namely NSP4 [ 22 ]. While a number of viroporins, virally-encoded proteins that modify host cell ion permeability, have been described [ 23 , 24 ], NSP4 was the first viral toxin discovered [ 25 , 26 ]. The mechanism of NSP4 action, and the regions of the protein responsible for its toxic properties have been identified [ 27 , 28 , 29 ].…”

Section: Introductionmentioning

confidence: 99%

Modeling of the Ebola Virus Delta Peptide Reveals a Potential Lytic Sequence Motif

Gallaher

Garry

2015

Viruses

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Filoviruses, such as Ebola and Marburg viruses, cause severe outbreaks of human infection, including the extensive epidemic of Ebola virus disease (EVD) in West Africa in 2014. In the course of examining mutations in the glycoprotein gene associated with 2014 Ebola virus (EBOV) sequences, a differential level of conservation was noted between the soluble form of glycoprotein (sGP) and the full length glycoprotein (GP), which are both encoded by the GP gene via RNA editing. In the region of the proteins encoded after the RNA editing site sGP was more conserved than the overlapping region of GP when compared to a distant outlier species, Tai Forest ebolavirus. Half of the amino acids comprising the “delta peptide”, a 40 amino acid carboxy-terminal fragment of sGP, were identical between otherwise widely divergent species. A lysine-rich amphipathic peptide motif was noted at the carboxyl terminus of delta peptide with high structural relatedness to the cytolytic peptide of the non-structural protein 4 (NSP4) of rotavirus. EBOV delta peptide is a candidate viroporin, a cationic pore-forming peptide, and may contribute to EBOV pathogenesis.

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“…PLA signals between NS1 and each of the CCC proteins in mosquito infected cells demonstrated be similar to the observed between CAV-1 and FKBP52, Cy40 and CyA [10]. CAV-1 dependent secretion have been reported for non-viral proteins such as Kallikrein 6 in Colon Cancer Cells and Cyr61 in lung cells [32,33] as well as non-structural viral proteins such as rotavirus NSP4 [34,35].…”

Section: Discussionmentioning

confidence: 60%

The dengue virus non-structural protein 1 (NS1) is secreted from mosquito cells in association with the intracellular cholesterol transporter chaperone caveolin complex

Ramirez

Ludert

2018

Preprint

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11 12 Keywords: 13 dengue virus; zika virus; yellow fever virus; flavivirus; NS1; caveolin-1; chaperone caveolin 14 complex; viral protein trafficking; unconventional secretion; mosquito cells 15 16 17 ABSTRACT 18 Dengue virus (DENV) is a mosquito-borne virus of the family Flaviviridae. The RNA viral genome 19 encodes for a polyprotein that is co-translationally processed into three structural proteins and . CC-BY 4.0 International license is made available under aThe copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/370932 doi: bioRxiv preprint 2 20 seven non-structural proteins. The non-structural protein 1 (NS1) is a multifunctional viral protein 21 actively secreted in vertebrate and mosquito cells during DENV infection. In mosquito cells, NS1 22 is secreted in a caveolin-1 (CAV-1) dependent manner by an unconventional pathway. The 23 caveolin chaperone complex (CCC) is a cytoplasmic complex formed by caveolin-1 and the 24 chaperones FKBP52, Cy40 and CyA which is responsible for cholesterol traffic inside the cell. 25 In this work, we demonstrate that in infected mosquito cells, DENV NS1 is secreted by an early 26 and unconventional route that bypasses the Golgi apparatus in close association with the CCC.27 Treatment of mosquito cells with classic secretion inhibitors such as brefeldin A, golgicide A and 28 Fli-06 showed no effect on NS1 secretion, but significant reductions in recombinant luciferase 29 secretion and virion release. Silencing the expression of CAV1, FKBP52 with siRNAs or the 30 inhibition of CyA by cyclosporine A resulted in significant decrease in NS1 secretion without 31 affecting virion release. Using co-localization, co-inmunoprecipitation and proximity ligation 32 assays, NS1 was found to co-localize and interact with all the protein components of the CCC 33 in mosquito infected cells. In addition, CAV-1 and FKBP52 expression was found augmented in 34 DENV infected cells. Finally, the treatment of ZIKV infected mosquito cells with brefeldin A and 35 golgicide A showed no effect on NS1 secretion, while affecting virion release. ZIKV NS1 was 36 also found to co-localize with CAV-1 in infected mosquito cells. These results suggest that in 37 mosquito cells, ZIKV NS1 follows the same secretory pathway observed for DENV NS1. The 38 association of NS1 with the cholesterol transporter CCC agrees with the lipoprotein nature of 39 secreted hexameric NS1. 40 41 AUTHOR SUMMARY . CC-BY 4.0 International license is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/370932 doi: bioRxiv preprint 3 42 Dengue protein NS1 is secreted in infected mosquito and vertebrate cells. In humans, secreted 43 NS1 have been associated with pathogenesis. In mosquito cells, NS1 follows an unconventional 44 secretion pathway that is dependent on Caveolin-1. This work shows that in mosquito cells, NS1 45 secretion is associated to the chaperone caveolin complex, a...

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Mutational analysis of the rotavirus NSP4 enterotoxic domain that binds to caveolin-1

Cited by 14 publications

References 51 publications

The Dengue Virus Nonstructural Protein 1 (NS1) Is Secreted from Mosquito Cells in Association with the Intracellular Cholesterol Transporter Chaperone Caveolin Complex

The Dengue Virus Nonstructural Protein 1 (NS1) Is Secreted from Mosquito Cells in Association with the Intracellular Cholesterol Transporter Chaperone Caveolin Complex

Modeling of the Ebola Virus Delta Peptide Reveals a Potential Lytic Sequence Motif

The dengue virus non-structural protein 1 (NS1) is secreted from mosquito cells in association with the intracellular cholesterol transporter chaperone caveolin complex

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