PubMed · 194565
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M A Mackenzie, B S Bains. 1977. Tenosynovitis in chickens.. https://doi.org/10.1111/j.1751-0813.1977.tb00180.x
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A variety of transcription factors are post-translationally modified by SUMO, a 97-residue ubiquitin-like protein bound covalently to the targeted lysine. Here we describe SUMO modification of the Ets family member ERM at positions 89, 263, 293, and 350. To investigate how SUMO modification affects the function of ERM, Ets-responsive intercellular adhesion molecule 1 (ICAM-1) and E74 reporter plasmids were employed to demonstrate that SUMO modification causes inhibition of ERM-dependent transcription without affecting the subcellular localization, stability, or DNA-binding capacity of the protein. When the adenoviral protein Gam1 or the SUMO protease SENP1 was used to inhibit the SUMO modification pathway, ERM-dependent transcription was de-repressed. These results demonstrate that ERM is subject to SUMO modification and that this post-translational modification causes inhibition of transcription-enhancing activity.
Bovine adenovirus type 3 (BAV3) is a DNA virus that causes respiratory and gastrointestinal disorders in cattle. The viral genome consists of a linear double-stranded DNA molecule (35,000 base pairs) with inverted terminal repeats at each of its 5' molecular ends. We have subcloned 10 HindIII fragments spanning 4.9-96.0%, 5 EcoRI fragments spanning 3.4-89.5% and 2 XbaI fragments spanning 35.7-82.9% of the BAV3 (strain WBR-1) genome into the bacterial cloning vector pUC19. The subcloning of the viral genome facilitated the construction of linear restriction enzyme maps for BamHI, ClaI, EcoRI, HindIII, KpnI, NotI, NspV, PstI, PvuI, SalI, XbaI and XhoI. In this study we report on the molecular cloning and restriction endonuclease mapping of the BAV3 genome.
The HIV Tat protein is a potent transactivator of HIV transcription, increasing both RNA initiation and elongation. We now demonstrate that purified, full-length 86 amino acid Tat protein specifically transactivates the HIV LTR in vitro to a high level (25- to 60-fold). Tat transactivation was specifically blocked by anti-Tat serum, but not preimmune serum. Tat did not transactivate transcription from the control adenovirus major late promoter (AdMLP). HIV transcription was blocked at various functional steps during initiation and elongation complex formation. Similar to the control AdMLP, HIV basal initiation complex assembly was sensitive to the addition of 0.015% sarkosyl prior to the addition of nucleoside triphosphates. Resistance to 0.05% sarkosyl required the addition of G, C, and U, which constitute the first 13 bases of the HIV RNA transcript. The addition of Tat to the in vitro transcription relieved the 0.015% sarkosyl block. These Tat-induced complexes were sensitive to 0.05% sarkosyl, suggesting that transcriptional initiation had not occurred. Consistent with this hypothesis, the addition of G, C, and U to the Tat-induced transcription complexes allowed the rapid conversion to transcription initiation complexes. Tat also facilitated the formation of 0.015% sarkosyl-resistant complexes in a reconstituted transcription system containing partially purified transcription factors and polymerase II. Following the formation of stable initiation complexes, Tat increased the rate and efficiency of transcription elongation on the HIV but not the AdML template. Kinetic analysis of Tat transactivation suggests that approximately 30% of the Tat initiation complexes are converted to elongation complexes. We conclude that Tat, in addition to its demonstrated role in RNA elongation, facilitates transcription initiation in vitro.