The relocalization of v-Rel from the nucleus to the cytoplasm coincides with induction of expression of Ikba and nfkb1 and stabilization of I kappa B-alpha.
The v-Rel oncogene induces the expression of major histocompatibility complex class I and II proteins and the interleukin-2 receptor more efficiently than does c-Rel (R. Hrdlicková, J. Nehyba, and E. H. Humphries, J. Virol. 68:308-319, 1994). The kinetics with which these immunoregulatory receptors are induced in B- and T-lymphoid cell lines and chicken embryo fibroblast cultures expressing c-Rel or v-Rel have been examined. v-Rel induced the expression of major histocompatibility complex classes I and II and interleukin-2 receptor more efficiently than did c-Rel at later times after infection. In all three cell types, this increased efficiency was accompanied by a shift in the majority of v-Rel from the nucleus of the cytoplasm. The concomitant relocalization of v-Rel was also demonstrated during the in vitro transformation of spleen cells. The translocation coincided with increased steady-state levels of I kappa B-alpha. Coninfection by retroviral vectors expressing v-Rel, I kappa B-alpha, or NF-kappa B1 demonstrated that either I kappa B-alpha can contribute to the shift of v-Rel to the cytoplasmic compartment. The induction of nfkb1 and Ikba mRNA and the stabilization of I kappa B-alpha by v-Rel were shown to be responsible for these effects. In comparison with c-Rel, the expression of v-Rel was associated with lower levels of transcription of these genes. However, the ability of v-Rel to stabilize I kappa B-alpha remained unchanged. The ability of v-Rel to stabilize I kappa B-alpha but poorly induce Ikba mRNA expression relative to c-Rel may play a role in regulating gene expression, thereby leading to transformation.
Hrdlicková
R
R
Department of Microbiology, University of Texas at Austin 78712-1095.
Nehyba
J
J
Roy
A
A
Humphries
E H
EH
Bose
H R
HR
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002642:Chick Embryo; D002645:Chickens; D003593:Cytoplasm / Q000378:metabolism; D005802:Genes, MHC Class II; D007700:Kinetics; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D020572:Oncogene Proteins v-rel; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D015375:Receptors, Interleukin-2 / Q000235:genetics; D015682:Retroviridae Proteins, Oncogenic / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D051841:Transcription Factor RelB; D014157:Transcription Factors
D016328:NF-kappa B; D020572:Oncogene Proteins v-rel; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D015682:Retroviridae Proteins, Oncogenic; D014157:Transcription Factors; D051841:Transcription Factor RelB