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[5] sites; sequence analysis of regulatory variants. [6] sites; mutational rearrangement in early control region;. [4] sites; enhancer-promoter sequence.
Draft entry and computer-readable sequence for [2] kindly provided by R.J.Frisque, 22-JAN-1987.
JCV is a polyomavirus more closely related to SV40 and ... BKV than to polyoma (PY). It can apparently cause the human disease progressive multifocal leukoencephalopathy and it can be highly oncogenic in primates. It grows well only in human fetal glial cells.
The E strand, having the polarity of the late mRNAs, is shown as it is reported in its entirety by [3]. That reference is also the primary source for the annotation herein, most of which is inferred by analogy with SV40 and BKV. The map units are calculated by
 JC + 3408
 mu = ------------- x 100,
 5130
where, as with other polyoma viruses, the single EcoRI site (at base 1722 ) is taken as 0.00%.
The mRNA start and end points are no more than putative: a possible promoter element ('TATA') for early mRNA initiation is found at base 22 on the comp strand, and similar elements for late mRNA initiation are found at bases 15 and 117.
As with BKV and SV40 (but not PY) the JC virus does not appear to encode a middle t-antigen; rather it appears to induce a host-cell specific middle t-antigen in transformed cells [3]. The Mad-1 strain of JCV is severely restricted in its growth in vitro. References [5], [6] and [4] show that mutations in the noncoding, regulatory region of the genome can affect host cell range. On the basis of seven independent isolates, [5] proposes that an enhancer segment (bases 12 to 207 below) is hypervariable. [6] has sequenced a fragment of an isolate (see separate entry) which has adapted to growth on originally nonpermissive human embryonic kidney cells; this form has an insertion of around 800 bp in the noncoding region near the origin of replication, yet can replicate DNA and direct large t-antigen synthesis in HEK cells. [4] specifically studies the enhancer region from bases 57 to 109 below, which is embedded in the first 98 bp tandem repeat; this sequence is shown to be homologous to an 82 bp rat brain-specific transcription factor.  more

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