Processing of SV40 RNA is associated with the nuclear matrix and is not followed by the accumulation of low-molecular-weight RNA products.

Nuclear matrices from SV40-infected cells were prepared by treating purified nuclei with DNase and salt to extract DNA and histones. After a 10-min pulse with [5,6(-3)H]uridine over 85% of the viral RNA was found in association with the nuclear matrix. Following a 3-hr chase with glucosamine and unlabeled uridine, 2-4 S nuclear viral components accumulate, but they are not associated with the nuclear matrix. The 2-4 S components had been characterized previously as viral RNA processing products (N. H. Chiu, M. F. Radonovich, M. M. Thoren, and N. P. Salzman, J. Virol. 28, 590-599, 1978). The results of the present study identify the 2-4 S components as DNA rather than RNA, thus indicating that the synthesis and the majority of the processing products of the viral RNA are associated with the nuclear matrix.