M. Hagmann et al., TRANSCRIPTION FACTORS INTERACTING WITH HERPES-SIMPLEX VIRUS ALPHA-GENE PROMOTERS IN SENSORY NEURONS, Nucleic acids research, 23(24), 1995, pp. 4978-4985
Interference with VP16-mediated activation of herpes virus immediate-e
arly (or alpha) genes is thought to be the major cause of establishing
viral latency in sensory neurons. This could be brought about by lack
of a key activating transcription factor(s) or active repression, In
this study we find that sensory neurons express all important componen
ts for VP16-mediated alpha gene induction, such as the POU transcripti
on factor Oct-1, host cell factor (HCF) and GABP alpha/beta, However,
Oct-1 and GABP alpha/beta are only present at low levels and the VP16-
induced complex (VIC) appears different, We do not find protein expres
sion of the transcription factor Oct-2, implicated by others as an alp
ha gene repressor, The POU factor N-Oct3 (Brn 2 or POU3F2) is also pre
sent in sensory neurons and binds viral TAATGARAT motifs with higher a
ffinity than Oct-1, indicating that it may be a candidate repressor fo
r competitive binding to TAATGARAT motifs, When transfected into HeLa
cells, where Oct-1 and GABP alpha/beta are highly abundant, N-Oct3 rep
resses model promoters with multimerized TAATGARAT motifs, but fails t
o repress complete a gene promoters, Taken together our findings sugge
st that modulation of alpha gene promoters could contribute to viral l
atency when low concentrations of the activating transcription factors
Oct-1 and GABP alpha/beta prevail, Our data, however, refute the noti
on that competing Oct factors are able to block ex gene transcription
to achieve viral latency.