I have studied: (1) the sequences involved in the transcription termination and 3$\sp\prime$ end formation of mouse histone mRNA, and (2) structural requirements for histone mRNA degradation. Histone mRNAs are not polyadenylated but end in a stem loop structure. To determine the sequences involved in the transcription termination and 3$\sp\prime$ end formation, the sequences in the 3$\sp\prime$ flanking region of the histone genes were modified and introduced into mouse L cells. The RNAs from transfected cells were detected by using S1 analysis. I have three independent pieces of evidence consistent with the identification of a transcription termination site. (1) I identified an RNA precursor in the nucleus of mouse L cells which is poly A$\sp-$ and ends about 600 nucleotides downstream of the normal 3$\sp\prime$ end. (2) The region where the transcription termination occurs was investigated by nuclear runoff experiments. This region coincided with the end of the primary transcript found in the nucleus. (3) The terminator sequences can block the expression of another histone gene and prevent the utilization of the globin poly A site placed downstream of it. I observed that both the stem loop structure and the purine rich sequences are required for 3$\sp\prime$ end formation of mouse histone mRNA. Deletion of this 3$\sp\prime$ processing signal abolished formation of the nuclear poly A$\sp-$ RNA. Instead, there are many transcripts resulting from RNA polymerase continuing past this termination site and ending after the stem loop of the downstream gene. These results suggested that transcription termination requires a functional 3$\sp\prime$ processing signal. / I have defined some histone RNAs which lack the stem loop at the 3$\sp\prime$ end, some of which contain this structure internally. None of these is subject to regulation of mRNA degradation. In addition, moving the stem loop 3$\sp\prime$ of the termination codon farther than 380 nucleotides results in stabilization of the histone mRNA, suggesting that the nuclease involved in mRNA turnover is associated with the ribosome. / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0724. / Major Professor: William F. Marzluff. / Thesis (Ph.D.)--The Florida State University, 1987.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76248 |
| Contributors | Chodchoy, Nunta., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 152 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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