I. Dix et Kn. Leppard, REGULATED SPLICING OF ADENOVIRUS TYPE-5 E4-TRANSCRIPTS AND REGULATED CYTOPLASMIC ACCUMULATION OF E4 MESSENGER-RNA, Journal of virology, 67(6), 1993, pp. 3226-3231
The E4 gene of human type C adenoviruses has been shown previously to
give rise to an array of mRNAs via differential splicing. In this stud
y, the pattern of expression of these mRNAs during lytic infection was
examined, and two distinct temporal classes were defined. mRNAs of th
e early class were distinguished from those of the late class by the p
resence, in the early class, of a sequence in the 3' half of the mRNA
that was removed as an intron in the late class. A single mRNA of the
late class was found to show a strong dependence on the presence of th
e 55-kDa protein from region E1b and the open reading frame 6 protein
from region E4 for its normal cytoplasmic accumulation. One feature of
this mRNA that distinguishes it from other E4 mRNAs expressed at late
times is the retention within it of an intron from the 5' half of E4;
it may therefore be recognized as incompletely spliced by the host ce
ll and retained in the nucleus. It is proposed that the E1b 55-kDa/E4
open reading frame 6 protein complex facilitates accumulation of this
mRNA by overcoming this retention mechanism.