Evidence for a role of the N-terminal domain in subcellular localization of the neuronal connexin36 (Cx36)

2002 ◽  
Vol 69 (4) ◽  
pp. 448-465 ◽  
Author(s):  
G. Zoidl ◽  
C. Meier ◽  
E. Petrasch-Parwez ◽  
C. Zoidl ◽  
H.-W. Habbes ◽  
...  
2016 ◽  
Vol 90 (16) ◽  
pp. 7131-7141 ◽  
Author(s):  
Tsuyoshi Hayashi ◽  
Chutikarn Chaimayo ◽  
James McGuinness ◽  
Toru Takimoto

ABSTRACTPA-X is a recently identified influenza virus protein that is composed of the PA N-terminal 191 amino acids and unique C-terminal 41 or 61 residues. We and others showed that PA-X has a strong ability to suppress host protein synthesis via host mRNA decay, which is mediated by endonuclease activity in its N-terminal domain (B. W. Jagger, H. M. Wise, J. C. Kash, K. A. Walters, N. M. Wills, Y. L. Xiao, R. L. Dunfee, L. M. Schwartzman, A. Ozinsky, G. L. Bell, R. M. Dalton, A. Lo, S. Efstathiou, J. F. Atkins, A. E. Firth, J. K. Taubenberger, and P. Digard, 2012, Science337:199–204,http://dx.doi.org/10.1126/science.1222213, and E. A. Desmet, K. A. Bussey, R. Stone, and T. Takimoto, 2013, J Virol87:3108–3118,http://dx.doi.org/10.1128/JVI.02826-12). However, the mechanism of host mRNA degradation, especially where and how PA-X targets mRNAs, has not been analyzed. In this study, we determined the localization of PA-X and the role of the C-terminal unique region in shutoff activity. Quantitative subcellular localization analysis revealed that PA-X was located equally in both cytoplasm and nucleus. By characterizing a series of PA-X C-terminal deletion mutants, we found that the first 9 amino acids were sufficient for nuclear localization, but an additional 6 residues were required to induce the maximum shutoff activity observed with intact PA-X. Importantly, forced nuclear localization of the PA-X C-terminal deletion mutant enhanced shutoff activity, highlighting the ability of nuclear PA-X to degrade host mRNAs more efficiently. However, PA-X also inhibited luciferase expression from transfected mRNAs synthesizedin vitro, suggesting that PA-X also degrades mRNAs in the cytoplasm. Among the basic amino acids in the PA-X C-terminal region, 3 residues, 195K, 198K, and 199R, were identified as key residues for inducing host shutoff and nuclear localization. Overall, our data indicate a critical role for the 15 residues in the PA-X C-terminal domain in degrading mRNAs in both the cytoplasm and nucleus.IMPORTANCEInfluenza A viruses express PA-X proteins to suppress global host gene expression, including host antiviral genes, to allow efficient viral replication in infected cells. However, little is known about how PA-X induces host shutoff. In this study, we showed that PA-X localized equally in both the cytoplasm and nucleus of the cells, but the nuclear localization of PA-X mediated by its C-terminal region has a significant impact on shutoff activity. Three basic residues at the C-terminal region play a critical role in nuclear localization, but additional basic residues were required for maximum shutoff activity. Our findings indicate that PA-X targets and degrades mRNAs in both the nucleus and cytoplasm, and that the first 15 residues of the PA-X unique C-terminal region play a critical role in shutoff activity.


1992 ◽  
Vol 267 (14) ◽  
pp. 9612-9618 ◽  
Author(s):  
G Murphy ◽  
J.A. Allan ◽  
F Willenbrock ◽  
M.I. Cockett ◽  
J.P. O'Connell ◽  
...  
Keyword(s):  

1992 ◽  
Vol 267 (29) ◽  
pp. 20965-20970
Author(s):  
K.M. Bohren ◽  
C.E. Grimshaw ◽  
K.H. Gabbay

2020 ◽  
Vol 402 (1) ◽  
pp. 89-98
Author(s):  
Nathalie Meiser ◽  
Nicole Mench ◽  
Martin Hengesbach

AbstractN6-methyladenosine (m6A) is the most abundant modification in mRNA. The core of the human N6-methyltransferase complex (MTC) is formed by a heterodimer consisting of METTL3 and METTL14, which specifically catalyzes m6A formation within an RRACH sequence context. Using recombinant proteins in a site-specific methylation assay that allows determination of quantitative methylation yields, our results show that this complex methylates its target RNAs not only sequence but also secondary structure dependent. Furthermore, we demonstrate the role of specific protein domains on both RNA binding and substrate turnover, focusing on postulated RNA binding elements. Our results show that one zinc finger motif within the complex is sufficient to bind RNA, however, both zinc fingers are required for methylation activity. We show that the N-terminal domain of METTL3 alters the secondary structure dependence of methylation yields. Our results demonstrate that a cooperative effect of all RNA-binding elements in the METTL3–METTL14 complex is required for efficient catalysis, and that binding of further proteins affecting the NTD of METTL3 may regulate substrate specificity.


2006 ◽  
Vol 281 (50) ◽  
pp. 38966
Author(s):  
Takashi Kinebuchi ◽  
Wataru Kagawa ◽  
Hitoshi Kurumizaka ◽  
Shigeyuki Yokoyama
Keyword(s):  

ChemMedChem ◽  
2011 ◽  
Vol 6 (7) ◽  
pp. 1207-1216 ◽  
Author(s):  
Andrea Cristiani ◽  
Giorgio Costa ◽  
Giorgio Cozza ◽  
Flavio Meggio ◽  
Leonardo Scapozza ◽  
...  

2014 ◽  
Vol 106 (2) ◽  
pp. 151a
Author(s):  
Sagar Chittori ◽  
Janesh Kumar ◽  
Suvendu Lomash ◽  
Huaying Zhao ◽  
Peter Schuck ◽  
...  

2007 ◽  
Vol 52 (3-4) ◽  
pp. 159-170 ◽  
Author(s):  
Simona Abba’ ◽  
Raffaella Balestrini ◽  
Alessandra Benedetto ◽  
Hanspeter Rottensteiner ◽  
José Ramón De Lucas ◽  
...  

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