PMID- 19467155
OWN - NLM
STAT- MEDLINE
DCOM- 20090803
LR  - 20211020
IS  - 1743-422X (Electronic)
IS  - 1743-422X (Linking)
VI  - 6
DP  - 2009 May 25
TI  - Hepatitis C virus NS4B carboxy terminal domain is a membrane binding domain.
PG  - 62
LID - 10.1186/1743-422X-6-62 [doi]
AB  - BACKGROUND: Hepatitis C virus (HCV) induces membrane rearrangements during 
      replication. All HCV proteins are associated to membranes, pointing out the 
      importance of membranes for HCV. Non structural protein 4B (NS4B) has been 
      reported to induce cellular membrane alterations like the membranous web. Four 
      transmembrane segments in the middle of the protein anchor NS4B to membranes. An 
      amphipatic helix at the amino-terminus attaches to membranes as well. The 
      carboxy-terminal domain (CTD) of NS4B is highly conserved in Hepaciviruses, 
      though its function remains unknown. RESULTS: A cytosolic localization is 
      predicted for the NS4B-CTD. However, using membrane floatation assays and 
      immunofluorescence, we now show targeting of the NS4B-CTD to membranes. 
      Furthermore, a profile-profile search, with an HCV NS4B-CTD multiple sequence 
      alignment, indicates sequence similarity to the membrane binding domain of 
      prokaryotic D-lactate dehydrogenase (d-LDH). The crystal structure of E. coli 
      d-LDH suggests that the region similar to NS4B-CTD is located in the membrane 
      binding domain (MBD) of d-LDH, implying analogy in membrane association. 
      Targeting of d-LDH to membranes occurs via electrostatic interactions of positive 
      residues on the outside of the protein with negative head groups of lipids. To 
      verify that anchorage of d-LDH MBD and NS4B-CTD is analogous, NS4B-CTD mutants 
      were designed to disrupt these electrostatic interactions. Membrane association 
      was confirmed by swopping the membrane contacting helix of d-LDH with the 
      corresponding domain of the 4B-CTD. Furthermore, the functionality of these 
      residues was tested in the HCV replicon system. CONCLUSION: Together these data 
      show that NS4B-CTD is associated to membranes, similar to the prokaryotic d-LDH 
      MBD, and is important for replication.
FAU - Liefhebber, Jolanda M P
AU  - Liefhebber JM
AD  - Department of Medical Microbiology, Center of Infectious Diseases, Leiden 
      University Medical Center, 2300 RC Leiden, The Netherlands. 
      J.M.P.Liefhebber@lumc.nl
FAU - Brandt, Bernd W
AU  - Brandt BW
FAU - Broer, Rene
AU  - Broer R
FAU - Spaan, Willy J M
AU  - Spaan WJ
FAU - van Leeuwen, Hans C
AU  - van Leeuwen HC
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20090525
PL  - England
TA  - Virol J
JT  - Virology journal
JID - 101231645
RN  - 0 (Escherichia coli Proteins)
RN  - 0 (NS4B protein, flavivirus)
RN  - 0 (Viral Nonstructural Proteins)
SB  - IM
MH  - Amino Acid Motifs
MH  - Amino Acid Sequence
MH  - Binding Sites
MH  - Cell Line
MH  - Cell Membrane/*virology
MH  - Escherichia coli Proteins/chemistry
MH  - Hepacivirus/*physiology
MH  - Humans
MH  - Models, Molecular
MH  - Molecular Sequence Data
MH  - Mutagenesis, Site-Directed
MH  - Protein Structure, Tertiary
MH  - Sequence Homology, Amino Acid
MH  - Viral Nonstructural Proteins/*metabolism
PMC - PMC2698844
EDAT- 2009/05/27 09:00
MHDA- 2009/08/04 09:00
PMCR- 2009/05/25
CRDT- 2009/05/27 09:00
PHST- 2009/03/10 00:00 [received]
PHST- 2009/05/25 00:00 [accepted]
PHST- 2009/05/27 09:00 [entrez]
PHST- 2009/05/27 09:00 [pubmed]
PHST- 2009/08/04 09:00 [medline]
PHST- 2009/05/25 00:00 [pmc-release]
AID - 1743-422X-6-62 [pii]
AID - 10.1186/1743-422X-6-62 [doi]
PST - epublish
SO  - Virol J. 2009 May 25;6:62. doi: 10.1186/1743-422X-6-62.