Participation of tfiiib subunit brf1 in transcription regulation in the human pathogen leishmania major
Por:
Florencio-Martinez, Luis E., Cano-Santiago, Andres, Mondragon-Rosas, Fabiola, Gomez-Garcia, Maricarmen, Flores-Perez, Carlos, Roman-Carraro, Fiordaliso C., Barocio-Rodriguez, Luis A., Manning-Cela, Rebeca G., Nepomuceno-Mejia, Tomas, Martinez-Calvillo, Santiago
Publicada:
1 ene 2021
Resumen:
In yeast and higher eukaryotes, transcription factor TFIIIB is required for accurate initiation of transcription by RNA Polymerase III (Pol III), which synthesizes transfer RNAs (tRNAs), 5S ribosomal RNA (rRNA), and other essential RNA molecules. TFIIIB is composed of three subunits: B double prime 1 (Bdp1), TATA-binding protein (TBP), and TFIIB-related factor 1 (Brf1). Here, we report the molecular characterization of Brf1 in Leishmania major (LmBrf1), a parasitic protozoan that shows distinctive transcription characteristics, including the apparent absence of Pol III general transcription factors TFIIIA and TFIIIC. Although single-knockout parasites of LmBrf1 were obtained, attempts to generate LmBrf1-null mutants were unsuccessful, which suggests that LmBrf1 is essential in promastigotes of L. major. Notably, Northern blot analyses showed that the half-lives of the messenger RNAs (mRNAs) from LmBrf1 and other components of the Pol III transcription machinery (Bdp1 and Pol III subunit RPC1) are very similar (~40 min). Stabilization of these transcripts was observed in stationary-phase parasites. Chromatin immunoprecipitation (ChIP) experiments showed that LmBrf1 binds to tRNA, small nuclear RNA (snRNA), and 5S rRNA genes. Unexpectedly, the results also indicated that LmBrf1 associates to the promoter region of the 18S rRNA genes and to three Pol II-dependent regions here analyzed. Tandem affinity purification and mass spectrometry analyses allowed the identification of a putative TFIIIC subunit. Moreover, several proteins involved in transcription by all three RNA polymerases co-purified with the tagged version of LmBrf1. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Filiaciones:
Florencio-Martinez, Luis E.:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Cano-Santiago, Andres:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Mondragon-Rosas, Fabiola:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Gomez-Garcia, Maricarmen:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Flores-Perez, Carlos:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Roman-Carraro, Fiordaliso C.:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Barocio-Rodriguez, Luis A.:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Manning-Cela, Rebeca G.:
Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Ciudad de Mexico, CP 07360, Mexico
Nepomuceno-Mejia, Tomas:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
Martinez-Calvillo, Santiago:
Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico, CP 54090, Mexico
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