TY - JOUR
T1 - Structure and dynamics of the second CARD of human RIG-I provide mechanistic insights into regulation of RIG-I activation
AU - Ferrage, Fabien
AU - Dutta, Kaushik
AU - Nistal-Villán, Estanislao
AU - Patel, Jenish R.
AU - Sánchez-Aparicio, María T.
AU - De Ioannes, Pablo
AU - Buku, Angeliki
AU - Aseguinolaza, Gloria González
AU - García-Sastre, Adolfo
AU - Aggarwal, Aneel K.
N1 - Funding Information:
We thank Richard Cadagan and Osman Lizardo (MSSM) as well as Roberto Ferrero Laborda (CIMA) for excellent technical assistance. We thank David Cowburn (Albert Einstein College of Medicine) and Wolfgang Peti (Brown University) for fruitful discussions. This work was partly supported by grants from the UTE project CIMA, JCI-2011-09179 to E. N.-V., and SAF2009-08524 (Ministerio de Ciencia e Innovación) to G.G.-A. This work was also partly supported by NIAID Grant U19AI083025 to A.G.-S. A.K.A. is a member of the New York Structural Biology Center. The data collection at NYSBC was made possible by a grant from NYSTAR, ORIP/NIH facility improvement Grant CO6RR015495, NIH Grant P41GM066354, the Keck Foundation, New York State, and the NYC Economic Development Corporation.
PY - 2012/12/5
Y1 - 2012/12/5
N2 - RIG-I is a cytosolic sensor of viral RNA, comprised of two N-terminal CARDs followed by helicase and C-terminal regulatory domains (helicase-CTD). Viral RNA binds to the helicase-CTD and "exposes" the CARDs for downstream signaling. The role of the second CARD (CARD2) is essential as RIG-I activation requires dephosphorylation of Thr170 followed by ubiquitination at Lys172. Here, we present the solution structure and dynamics of human RIG-I CARD2. Surprisingly, we find that Thr170 is mostly buried. Parallel studies on the phosphomimetic T170E mutant suggest that the loss of function upon Thr170 phosphorylation is likely associated with changes in the CARD1-CARD2 interface that may prevent Lys172 ubiquitination and/or binding to free K63-linked polyubiquitin. We also demonstrate a strong interaction between CARD2 and the helicase-CTD, and show that mutations at the interface result in constitutive activation of RIG-I. Collectively, our data suggests a close interplay between phosphorylation, ubiquitination, and activation of human RIG-I, all mediated by CARD2.
AB - RIG-I is a cytosolic sensor of viral RNA, comprised of two N-terminal CARDs followed by helicase and C-terminal regulatory domains (helicase-CTD). Viral RNA binds to the helicase-CTD and "exposes" the CARDs for downstream signaling. The role of the second CARD (CARD2) is essential as RIG-I activation requires dephosphorylation of Thr170 followed by ubiquitination at Lys172. Here, we present the solution structure and dynamics of human RIG-I CARD2. Surprisingly, we find that Thr170 is mostly buried. Parallel studies on the phosphomimetic T170E mutant suggest that the loss of function upon Thr170 phosphorylation is likely associated with changes in the CARD1-CARD2 interface that may prevent Lys172 ubiquitination and/or binding to free K63-linked polyubiquitin. We also demonstrate a strong interaction between CARD2 and the helicase-CTD, and show that mutations at the interface result in constitutive activation of RIG-I. Collectively, our data suggests a close interplay between phosphorylation, ubiquitination, and activation of human RIG-I, all mediated by CARD2.
UR - https://www.scopus.com/pages/publications/84870502910
U2 - 10.1016/j.str.2012.09.003
DO - 10.1016/j.str.2012.09.003
M3 - Article
C2 - 23063562
AN - SCOPUS:84870502910
SN - 0969-2126
VL - 20
SP - 2048
EP - 2061
JO - Structure
JF - Structure
IS - 12
ER -