Epstein–Barr virus latent membrane protein 2
Epstein–Barr virus (EBV) latent membrane protein 2 (LMP2) are two
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.[3] 1.7 kb and 2.0 kb messages are created by alternative promoter usage and differ only in the sequences of the first exon.[4] 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.[1] 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.[3]
LMP2A protein interactions
The 119 amino-terminal cytoplasmic domain of LMP2A has several motifs that mediate interactions between proteins, including eight tyrosine residues. Two motifs that are centered on Y74 and Y85 are spaced 7 residues apart to form an immunoreceptor tyrosine-based activation motif (ITAM) commonly found in Fc receptors and signal molecules of B-cell and T-cell receptors. Receptor docking with molecules containing cytoplasmic tyrosine kinases is governed by
LMP2A function
LMP2B
Eight exons of LMP2 isoforms encode 12 membrane spanning segments that are connected by short