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LC-MS/MS analysis of immunoprecipitation samples of a Tetrahymena TFIIB-like protein Emit3 and the zinc-ribbon mutated Emit3

ABSTRACT: Transposable elements (TEs) are threats to genome stability and thus small RNA-mediated heterochromatinization suppresses the transcription of TEs. Paradoxically, transcription of non-coding RNA (ncRNA) from TEs is needed for the production of TE-targeting small RNAs and/or recruiting the silencing machinery to TEs. Hence, specialized RNA polymerase II (Pol II) transcription machinery is required for such unconventional transcription in different organisms. Indeed, the developmental stage-specific Mediator complex (Med)-associated proteins play essential roles in the ncRNA transcription from TE-related sequences in Tetrahymena. Yet it remains unknown how those Med-associated proteins are linked to the TE transcription by Pol II. Here, have found that Pol II is regulated by Emit3, a stage-specific, TFIIB-like protein specialized in TE transcription. Hence, to find out potential interactions, we did LC-MS/MS analysis for immunoprecipitation samples of Emit3 and the zinc-ribbon mutated Emit3.

INSTRUMENT(S):

ORGANISM(S): Tetrahymena Thermophila

TISSUE(S): Cell Culture

SUBMITTER: Miao TIAN

LAB HEAD: Miao TIAN

PROVIDER: PXD057568 | Pride | 2025-05-13

REPOSITORIES: Pride

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			Action	DRS
	20160509_QexHF4_RSLC4_Tian_Loidl_MFPL_coom_CoIP_MIP_25per.mgf	Mgf
	20160509_QexHF4_RSLC4_Tian_Loidl_MFPL_coom_CoIP_MIP_25per.raw	Raw
	20160509_QexHF4_RSLC4_Tian_Loidl_MFPL_coom_CoIP_WT_25per.mgf	Mgf
	20160509_QexHF4_RSLC4_Tian_Loidl_MFPL_coom_CoIP_WT_25per.raw	Raw
	20160627_QexHF4_RSLC4_Tian_Loidl_MFPL_coom_sample1_2MIP1_C3_25per.mgf	Mgf

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LC-MS/MS analysis of immunoprecipitation samples of Tetrahymena Mediator complex associated proteins

Project description:In the germline nucleus of Tetrahymena and other ciliates there occurs a peculiar burst of transcriptional activity during sexual reproduction. A major part of the genome is transcribed into noncoding RNA (ncRNA). This ncRNA serves to spot transposable elements (TEs) and other unwanted DNA sequences and marks them for elimination from the soma of the progeny. ncRNA transcription is remarkable for its extent, its occurrence in a nucleus that bears heterochromatic marks and is incapable of transcribing mRNAs and for its concomitance with meiotic DNA recombination. Here we report two novel factors (Emit1 and Emit2) that promote the micronuclear localization of the transcription Mediator complex to allow this unconventional transcriptional program to occur. Another factor (Rib1) may enhance the transcription activity to TE-rich pericentromeric and telomeric regions. The purpose of the LC-MS/MS analysis of Emit1, Emit2 and Rib1 immunoprecipitation samples is to identify their potential interacting partner proteins.

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