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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Stress Induces Changes in the Phosphorylation of Trypanosoma cruzi RNA Polymerase II, Affecting Its Association with Chromatin and RNA Processing

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Author(s):
Rocha, Antonio Augusto [1] ; Moretti, Nilmar Silvio [1] ; Schenkman, Sergio [1]
Total Authors: 3
Affiliation:
[1] Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Eukaryotic Cell; v. 13, n. 7, p. 855-865, JUL 2014.
Web of Science Citations: 2
Abstract

The phosphorylation of the carboxy-terminal heptapeptide repeats of the largest subunit of RNA polymerase II (Pol II) controls several transcription-related events in eukaryotes. Trypanosomatids lack these typical repeats and display an unusual transcription control. RNA Pol II associates with the transcription site of the spliced leader (SL) RNA, which is used in the trans-splicing of all mRNAs transcribed on long polycistronic units. We found that Trypanosoma cruzi RNA Pol II associated with chromatin is highly phosphorylated. When transcription is inhibited by actinomycin D, the enzyme runs off from SL genes, remaining hyperphosphorylated and associated with polycistronic transcription units. Upon heat shock, the enzyme is dephosphorylated and remains associated with the chromatin. Transcription is partially inhibited with the accumulation of housekeeping precursor mRNAs, except for heat shock genes. DNA damage caused dephosphorylation and transcription arrest, with RNA Pol II dissociating from chromatin although staying at the SL. In the presence of calyculin A, the hyperphosphorylated form detached from chromatin, including the SL loci. These results indicate that in trypanosomes, the unusual RNA Pol II is phosphorylated during the transcription of SL and polycistronic operons. Different types of stresses modify its phosphorylation state, affecting pre-RNA processing. (AU)

FAPESP's process: 11/51973-3 - Cell signaling mechanism of Trypanosoma in response to nutritional alterations and genotoxic agents
Grantee:Sergio Schenkman
Support Opportunities: Research Projects - Thematic Grants