Epstein–Barr virus latent membrane protein 2
Epstein–Barr virus (EBV) latent membrane protein 2 (LMP2) are two viral proteins of the Epstein–Barr virus. LMP2A/LMP2B are transmembrane proteins that act to block tyrosine kinase signaling. LMP2A is a transmembrane protein that inhibits normal B-cell signal transduction by mimicking an activated B-cell receptor (BCR). The N-terminus domain of LMP2A is tyrosine phosphorylated and associates with Src family protein tyrosine kinases (PTKs) as well as spleen tyrosine kinase (Syk). PTKs and Syk are associated with BCR signal transduction.
LMP2 Gene Structure and Expression
Latent Membrane Protein 2 (LMP2) is a rightward transcribing gene. LMP2’s transcript originates across the fused terminal repeats in sequences at opposite ends of the genome. 16–24 hours after infection, the genome circularizes and the open reading frame is created. 1.7 kb and 2.0 kb messages are created by alternative promoter usage and differ only in the sequences of the first exon. These messages are expressed in Epstein-Barr Virus transformed lymphoblastoid cell cultures. The ratio of these messages varies widely and unpredictably suggesting little co-ordinate control of promoter activity or mRNA abundance. Residues 497 (LMP2A) and 378 (LMP2B) are encoded by these two messages. These two iso forms of LMP2 only differ in that LMP2A contains an extra 119 residue N-terminal domain encoded in exon 1. LMP2B’s first exon is non coding. Initiation of translation is presumed to occur at the first available [methionine] that is in-frame in exon two. Twelve membrane spanning segments ending with a short 28 residue COOH tail are common to both proteins in residue 379.
Le Mans Prototype
A Le Mans Prototype (LMP) is the type of sports prototype race car used in the 24 Hours of Le Mans, FIA World Endurance Championship, United SportsCar Championship, European Le Mans Series and Asian Le Mans Series. Le Mans Prototypes were created by the Automobile Club de l'Ouest (ACO). The technical requirements for an LMP include bodywork covering all mechanical elements of the car.
While not as fast as open-wheel Formula One cars, LMPs are the fastest closed-wheel racing cars used in circuit racing. Le Mans Prototypes are considered a class above production-based grand tourer cars, which compete alongside them in sports car racing.
Modern LMP designs include hybrid cars that use electric motors to assist acceleration.
Name variations
Le Mans Prototypes have used various names depending on the series in which they compete. The FIA's equivalent cars were referred to as Sports Racers (SR) or Sports Racing Prototypes (SRP). The American IMSA GT Championship termed their cars World Sports Cars' (WSC), while the short-lived United States Road Racing Championship used the classic Can-Am (CA) name for their prototypes. Since 2004, most series have switched to referring to these cars as Le Mans Prototypes. The American Le Mans Series, the successor to the IMSA GT Championship and the predecessor of the TUDOR United SportsCar Championship, officially referred to the cars simply as Prototypes (P1, P2, or PC). An LMP is commonly referred to as a Le Mans car in the media.
Epstein–Barr virus latent membrane protein 1
Epstein–Barr virus latent membrane protein 1 (LMP1) is an Epstein–Barr virus (EBV) protein that regulates its own expression and the expression of human genes. LMP1 has a molecular weight of approximately 63 kDa, and its expression induces many of the changes associated with EBV infections and activation of primary B cells. LMP1 is the best-documented oncoprotein of the EBV latent gene products, as it is expressed in most EBV-related human cancers.
The structure of LMP1 consists of a short cytoplasmic N-terminus tail, six trans-membrane domains, and a long cytoplasmic C-terminus, which contains three activating domains: CTARt, CTAR2, and CTAR3. Each CTAR domain contains an amino acid sequence that serves as a recognition site for cellular adaptors to bind and trigger a series of signal transduction pathways that can lead to a change in gene expression.
LMP-1 mediates signaling through the tumor necrosis factor-alpha/CD40 pathway.
It is often found in Reed–Sternberg cells.
