PMID- 25564465
OWN - NLM
STAT- MEDLINE
DCOM- 20160314
LR  - 20191227
IS  - 2150-7511 (Electronic)
VI  - 6
IP  - 1
DP  - 2015 Jan 6
TI  - Membrane anchoring of Epstein-Barr virus gp42 inhibits fusion with B cells even 
      with increased flexibility allowed by engineered spacers.
LID - 10.1128/mBio.02285-14 [doi]
LID - e02285-14
AB  - We recently described the architecture of the Epstein-Barr virus (EBV) 
      fusion-triggering complex consisting of the EBV B cell receptor human leukocyte 
      antigen (HLA) class II and the EBV-encoded proteins gp42 and gH/gL. The 
      architecture of this structure positioned the main body of gp42, comprising the 
      C-type lectin domain (CTLD), away from the membrane and distant from where the 
      membrane-bound form of gp42 might be tethered. gp42 is a type II membrane 
      glycoprotein, with functional gp42 formed by cleavage near the gp42 
      amino-terminal transmembrane domain. This cleavage results in an approximately 
      50-amino-acid unstructured region that is responsible for binding gH/gL with 
      nanomolar affinity. Our previous studies had shown that membrane-bound gp42 is 
      not functional in B cell fusion. To investigate whether we could restore gp42 
      function by extending it from the membrane, we introduced one, two, and four 
      structured immunoglobulin-like domains from muscle protein titin into a 
      membrane-bound form of gp42 and tested function in binding to gHgL and HLA class 
      II and function in fusion. We hypothesized that cleavage of gp42 generates a 
      soluble functional form that relieves steric hindrance imposed on gHgL by 
      membrane-bound gp42. All of the linker mutants had a dominant-negative effect on 
      gp42 function, indicating that gp42 fusion function could not be restored simply 
      by the addition of one to four titin domains. IMPORTANCE: Epstein-Barr virus 
      (EBV) is associated with numerous diseases from benign mononucleosis to Burkitt's 
      and Hodgkin's lymphoma, nasopharyngeal and gastric carcinoma, and 
      lymphoproliferative disorders in patients with immune dysfunction resulting from 
      immune suppression. Among the glycoproteins important for fusion, gp42, along 
      with gH/gL, determines EBV tropism between epithelial and B cells. The function 
      of gp42 is dependent on N-terminal cleavage, since membrane-bound gp42 cannot 
      mediate fusion. We further investigated whether insertion of a linker into 
      membrane-bound gp42 would relieve steric hindrance imposed on membrane-bound gp42 
      and restore fusion function. However, adding one, two, or four structured 
      immunoglobulin-like domains to membrane gp42 did not restore fusion activity, 
      indicating that the architecture and membrane orientation of the B cell 
      fusion-triggering complex of EBV may be easily perturbed and that gp42 cleavage 
      is essential for B cell fusion.
CI  - Copyright (c) 2015 Rowe et al.
FAU - Rowe, Cynthia L
AU  - Rowe CL
AD  - Department of Microbiology and Immunology, Feinberg School of Medicine, 
      Northwestern University, Chicago, Illinois, USA.
FAU - Chen, Jia
AU  - Chen J
AD  - Department of Microbiology and Immunology, Feinberg School of Medicine, 
      Northwestern University, Chicago, Illinois, USA.
FAU - Jardetzky, Theodore S
AU  - Jardetzky TS
AD  - Department of Structural Biology, Stanford University School of Medicine, 
      Stanford, California, USA.
FAU - Longnecker, Richard
AU  - Longnecker R
AD  - Department of Microbiology and Immunology, Feinberg School of Medicine, 
      Northwestern University, Chicago, Illinois, USA r-longnecker@northwestern.edu.
LA  - eng
GR  - AI076183/AI/NIAID NIH HHS/United States
GR  - R01 CA117794/CA/NCI NIH HHS/United States
GR  - R01 CA133063/CA/NCI NIH HHS/United States
GR  - CA117794/CA/NCI NIH HHS/United States
GR  - P30 CA060553/CA/NCI NIH HHS/United States
GR  - R01 AI076183/AI/NIAID NIH HHS/United States
GR  - CA133063/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20150106
PL  - United States
TA  - mBio
JT  - mBio
JID - 101519231
RN  - 0 (Glycoproteins)
RN  - 0 (Membrane Glycoproteins)
RN  - 0 (Molecular Chaperones)
RN  - 0 (Viral Envelope Proteins)
RN  - 0 (Viral Proteins)
RN  - 0 (glycoprotein H, Herpesvirus 4)
RN  - 0 (glycoprotein L, Human herpesvirus 4)
SB  - IM
MH  - B-Lymphocytes/*virology
MH  - Cell Fusion
MH  - Cell Membrane/*virology
MH  - Epstein-Barr Virus Infections/*virology
MH  - Glycoproteins/chemistry/genetics/*metabolism
MH  - Herpesvirus 4, Human/chemistry/genetics/*physiology
MH  - Humans
MH  - Membrane Glycoproteins/genetics/metabolism
MH  - Molecular Chaperones/genetics/metabolism
MH  - Protein Structure, Tertiary
MH  - Viral Envelope Proteins/genetics/metabolism
MH  - Viral Proteins/chemistry/genetics/*metabolism
MH  - Virus Internalization
PMC - PMC4313908
EDAT- 2015/01/08 06:00
MHDA- 2016/03/15 06:00
PMCR- 2015/01/06
CRDT- 2015/01/08 06:00
PHST- 2015/01/08 06:00 [entrez]
PHST- 2015/01/08 06:00 [pubmed]
PHST- 2016/03/15 06:00 [medline]
PHST- 2015/01/06 00:00 [pmc-release]
AID - mBio.02285-14 [pii]
AID - mBio02285-14 [pii]
AID - 10.1128/mBio.02285-14 [doi]
PST - epublish
SO  - mBio. 2015 Jan 6;6(1):e02285-14. doi: 10.1128/mBio.02285-14.