Differential expression and localization of EBER-1 and EBER-2 in Epstein-Barr virus-carrying cells.
OBJECTIVE
The functions of the Epstein-Barr virus (EBV)-encoded small RNAs (EBER-1 and EBER-2) are unknown. We examined their fine intranuclear localization as the first step to investigate their function.


METHODS
We analyzed EBER-1 and EBER-2 by in situ hybridization combined with two-color immunofluorescence tagging.


RESULTS
EBER-1 was visualized as fine dots, mainly in the euchromatin. Ribosomal protein L-22 also formed fine dots, similar to those formed by EBER-1, in the nuclei of EBV-carrying cells and colocalized with the latter by double staining. EBER-2 was predominantly found in the nucleoli and was also present in the euchromatin. The two EBERs were similarly expressed in B-cell lines of the different phenotypes examined. The EBERs showed no colocalization by double staining. Image analysis indicated that the level of their expression was not correlated.


CONCLUSIONS
The differential localization and expression of the EBER-1 and EBER-2 suggests that they may play different functional roles.
Teramoto
N
N
Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden. teramoto.norihiro@mtc.ki.se
Szekely
L
L
Klein
G
G
D000818:Animals; D002460:Cell Line / Q000821:virology; D002467:Cell Nucleus / Q000821:virology; D003593:Cytoplasm / Q000821:virology; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D016393:Lymphoma, B-Cell / Q000821:virology; D012367:RNA, Viral / Q000032:analysis*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012269:Ribosomal Proteins
C099537:Epstein-Barr virus encoded RNA 1; C106732:Epstein-Barr virus encoded RNA 2; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C067169:RPL22 protein, human