Kaposi's sarcoma associated herpesvirus encoded viral flice inhibitory protein K13 activates NF-κB pathway independent of TRAF6, TAK1 and LUBAC

Hittu Matta, Ramakrishnan Gopalakrishnan, Ciaren Graham, Bhairavi Tolani, Akshat Khanna, Han Yi, Yulan Suo, Preet M. Chaudhary

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Background: Kaposi's sarcoma associated herpesvirus encoded viral FLICE inhibitory protein (vFLIP) K13 activates the NF-κB pathway by binding to the NEMO/IKKγ subunit of the IκB kinase (IKK) complex. However, it has remained enigmatic how K13-NEMO interaction results in the activation of the IKK complex. Recent studies have implicated TRAF6, TAK1 and linear ubiquitin chains assembled by a linear ubiquitin chain assembly complex (LUBAC) consisting of HOIL-1, HOIP and SHARPIN in IKK activation by proinflammatory cytokines. Methodology/Principal Findings: Here we demonstrate that K13-induced NF-κB DNA binding and transcriptional activities are not impaired in cells derived from mice with targeted disruption of TRAF6, TAK1 and HOIL-1 genes and in cells derived from mice with chronic proliferative dermatitis (cpdm), which have mutation in the Sharpin gene (Sharpincpdm/cpdm). Furthermore, reconstitution of NEMO-deficient murine embryonic fibroblast cells with NEMO mutants that are incapable of binding to linear ubiquitin chains supported K13-induced NF-κB activity. K13-induced NF-κB activity was not blocked by CYLD, a deubiquitylating enzyme that can cleave linear and Lys63-linked ubiquitin chains. On the other hand, NEMO was required for interaction of K13 with IKK1/IKKα and IKK2/IKKβ, which resulted in their activation by "T Loop" phosphorylation. Conclusions/Significance: Our results demonstrate that K13 activates the NF-κB pathway by binding to NEMO which results in the recruitment of IKK1/IKKα and IKK2/IKKβ and their subsequent activation by phosphorylation. Thus, K13 activates NF-κB via a mechanism distinct from that utilized by inflammatory cytokines. These results have important implications for the development of therapeutic agents targeting K13-induced NF-κB for the treatment of KSHV-associated malignancies.

Original languageEnglish
Article numbere36601
JournalPLoS ONE
Volume7
Issue number5
DOIs
Publication statusPublished - 08 May 2012
Externally publishedYes

Fingerprint

IKappaB kinase
Human herpesvirus 8
TNF Receptor-Associated Factor 6
Human Herpesvirus 8
ubiquitin
Ubiquitin
Chemical activation
Dermatitis
Phosphorylation
Proteins
proteins
Genes
CASP8 and FADD-Like Apoptosis Regulating Protein
Cytokines
Viral Proteins
Fibroblasts
dermatitis
phosphorylation
mice
cytokines

Cite this

Matta, Hittu ; Gopalakrishnan, Ramakrishnan ; Graham, Ciaren ; Tolani, Bhairavi ; Khanna, Akshat ; Yi, Han ; Suo, Yulan ; Chaudhary, Preet M. / Kaposi's sarcoma associated herpesvirus encoded viral flice inhibitory protein K13 activates NF-κB pathway independent of TRAF6, TAK1 and LUBAC. In: PLoS ONE. 2012 ; Vol. 7, No. 5.
@article{c7d7e82c1e184a2b8394a4c329677808,
title = "Kaposi's sarcoma associated herpesvirus encoded viral flice inhibitory protein K13 activates NF-κB pathway independent of TRAF6, TAK1 and LUBAC",
abstract = "Background: Kaposi's sarcoma associated herpesvirus encoded viral FLICE inhibitory protein (vFLIP) K13 activates the NF-κB pathway by binding to the NEMO/IKKγ subunit of the IκB kinase (IKK) complex. However, it has remained enigmatic how K13-NEMO interaction results in the activation of the IKK complex. Recent studies have implicated TRAF6, TAK1 and linear ubiquitin chains assembled by a linear ubiquitin chain assembly complex (LUBAC) consisting of HOIL-1, HOIP and SHARPIN in IKK activation by proinflammatory cytokines. Methodology/Principal Findings: Here we demonstrate that K13-induced NF-κB DNA binding and transcriptional activities are not impaired in cells derived from mice with targeted disruption of TRAF6, TAK1 and HOIL-1 genes and in cells derived from mice with chronic proliferative dermatitis (cpdm), which have mutation in the Sharpin gene (Sharpincpdm/cpdm). Furthermore, reconstitution of NEMO-deficient murine embryonic fibroblast cells with NEMO mutants that are incapable of binding to linear ubiquitin chains supported K13-induced NF-κB activity. K13-induced NF-κB activity was not blocked by CYLD, a deubiquitylating enzyme that can cleave linear and Lys63-linked ubiquitin chains. On the other hand, NEMO was required for interaction of K13 with IKK1/IKKα and IKK2/IKKβ, which resulted in their activation by {"}T Loop{"} phosphorylation. Conclusions/Significance: Our results demonstrate that K13 activates the NF-κB pathway by binding to NEMO which results in the recruitment of IKK1/IKKα and IKK2/IKKβ and their subsequent activation by phosphorylation. Thus, K13 activates NF-κB via a mechanism distinct from that utilized by inflammatory cytokines. These results have important implications for the development of therapeutic agents targeting K13-induced NF-κB for the treatment of KSHV-associated malignancies.",
author = "Hittu Matta and Ramakrishnan Gopalakrishnan and Ciaren Graham and Bhairavi Tolani and Akshat Khanna and Han Yi and Yulan Suo and Chaudhary, {Preet M.}",
year = "2012",
month = "5",
day = "8",
doi = "10.1371/journal.pone.0036601",
language = "English",
volume = "7",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science (PLOS)",
number = "5",

}

Kaposi's sarcoma associated herpesvirus encoded viral flice inhibitory protein K13 activates NF-κB pathway independent of TRAF6, TAK1 and LUBAC. / Matta, Hittu; Gopalakrishnan, Ramakrishnan; Graham, Ciaren; Tolani, Bhairavi; Khanna, Akshat; Yi, Han; Suo, Yulan; Chaudhary, Preet M.

In: PLoS ONE, Vol. 7, No. 5, e36601, 08.05.2012.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Kaposi's sarcoma associated herpesvirus encoded viral flice inhibitory protein K13 activates NF-κB pathway independent of TRAF6, TAK1 and LUBAC

AU - Matta, Hittu

AU - Gopalakrishnan, Ramakrishnan

AU - Graham, Ciaren

AU - Tolani, Bhairavi

AU - Khanna, Akshat

AU - Yi, Han

AU - Suo, Yulan

AU - Chaudhary, Preet M.

PY - 2012/5/8

Y1 - 2012/5/8

N2 - Background: Kaposi's sarcoma associated herpesvirus encoded viral FLICE inhibitory protein (vFLIP) K13 activates the NF-κB pathway by binding to the NEMO/IKKγ subunit of the IκB kinase (IKK) complex. However, it has remained enigmatic how K13-NEMO interaction results in the activation of the IKK complex. Recent studies have implicated TRAF6, TAK1 and linear ubiquitin chains assembled by a linear ubiquitin chain assembly complex (LUBAC) consisting of HOIL-1, HOIP and SHARPIN in IKK activation by proinflammatory cytokines. Methodology/Principal Findings: Here we demonstrate that K13-induced NF-κB DNA binding and transcriptional activities are not impaired in cells derived from mice with targeted disruption of TRAF6, TAK1 and HOIL-1 genes and in cells derived from mice with chronic proliferative dermatitis (cpdm), which have mutation in the Sharpin gene (Sharpincpdm/cpdm). Furthermore, reconstitution of NEMO-deficient murine embryonic fibroblast cells with NEMO mutants that are incapable of binding to linear ubiquitin chains supported K13-induced NF-κB activity. K13-induced NF-κB activity was not blocked by CYLD, a deubiquitylating enzyme that can cleave linear and Lys63-linked ubiquitin chains. On the other hand, NEMO was required for interaction of K13 with IKK1/IKKα and IKK2/IKKβ, which resulted in their activation by "T Loop" phosphorylation. Conclusions/Significance: Our results demonstrate that K13 activates the NF-κB pathway by binding to NEMO which results in the recruitment of IKK1/IKKα and IKK2/IKKβ and their subsequent activation by phosphorylation. Thus, K13 activates NF-κB via a mechanism distinct from that utilized by inflammatory cytokines. These results have important implications for the development of therapeutic agents targeting K13-induced NF-κB for the treatment of KSHV-associated malignancies.

AB - Background: Kaposi's sarcoma associated herpesvirus encoded viral FLICE inhibitory protein (vFLIP) K13 activates the NF-κB pathway by binding to the NEMO/IKKγ subunit of the IκB kinase (IKK) complex. However, it has remained enigmatic how K13-NEMO interaction results in the activation of the IKK complex. Recent studies have implicated TRAF6, TAK1 and linear ubiquitin chains assembled by a linear ubiquitin chain assembly complex (LUBAC) consisting of HOIL-1, HOIP and SHARPIN in IKK activation by proinflammatory cytokines. Methodology/Principal Findings: Here we demonstrate that K13-induced NF-κB DNA binding and transcriptional activities are not impaired in cells derived from mice with targeted disruption of TRAF6, TAK1 and HOIL-1 genes and in cells derived from mice with chronic proliferative dermatitis (cpdm), which have mutation in the Sharpin gene (Sharpincpdm/cpdm). Furthermore, reconstitution of NEMO-deficient murine embryonic fibroblast cells with NEMO mutants that are incapable of binding to linear ubiquitin chains supported K13-induced NF-κB activity. K13-induced NF-κB activity was not blocked by CYLD, a deubiquitylating enzyme that can cleave linear and Lys63-linked ubiquitin chains. On the other hand, NEMO was required for interaction of K13 with IKK1/IKKα and IKK2/IKKβ, which resulted in their activation by "T Loop" phosphorylation. Conclusions/Significance: Our results demonstrate that K13 activates the NF-κB pathway by binding to NEMO which results in the recruitment of IKK1/IKKα and IKK2/IKKβ and their subsequent activation by phosphorylation. Thus, K13 activates NF-κB via a mechanism distinct from that utilized by inflammatory cytokines. These results have important implications for the development of therapeutic agents targeting K13-induced NF-κB for the treatment of KSHV-associated malignancies.

UR - http://www.scopus.com/inward/record.url?scp=84860672660&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0036601

DO - 10.1371/journal.pone.0036601

M3 - Article

C2 - 22590573

AN - SCOPUS:84860672660

VL - 7

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 5

M1 - e36601

ER -