MassIVE MSV000083465

Complete Public PXD012807

MudPIT analyses of the proteins co-purified with the Interactor of Little Elongation Complex ELL subunit 1 (FLAG-ICE1), WT MED26, and D2G8 NTD-mutant MED26, affinity-purified from HEK293T cell lines

Description

Protein Complexes Purification: We generated 293FRT cell lines that stably express FLAG-tagged ICE1 (Interactor of Little Elongation Complex ELL subunit 1; KIAA0947). We extracted nuclear proteins in the presence of Benzonase to digest nucleic acids, including both DNA and RNA, and purified the little elongation complex (LEC) through anti-FLAG affinity purification using anti-FLAG M2 agarose. Cells only expressing the FLAG epitope-tag were analyzed in parallel as negative controls. A MED26 hypomorphic HEK293T cell line D2G8 was generated by applying multiple small guide RNAs (sgRNAs) complementary to the MED26 gene to induce random sequence insertions and/or deletions. This cell line expresses mutant MED26 lacking the NTD. Mediator was purified from cells expressing either WT MED26 or D2G8 MED26 via its ability to bind the transcriptional activation domain of ATF6-alpha. Proteins were precipitated with 1/5 TCA overnight at 4oC and washed 2x with cold acetone. Multidimensional Protein Identification Technology: TCA-precipitated protein pellets were with Tris-HCl pH 8.5 8 M urea, followed by addition of TCEP (Pierce) and chloroacetamide (Sigma) to a final concentration of 5 mM and 10 mM, respectively. Proteins were digested using Endoproteinase Lys-C (Roche) at 37oC overnight. The samples were brought to a final concentration of 2 M urea and 2 mM CaCl2 and a second digestion was performed overnight at 37oC using trypsin (Promega). Digested peptides were loaded on a split-triple-phase fused-silica micro-capillary column and placed in-line with a linear ion trap mass spectrometer (LTQ, Thermo Scientific), coupled with a Quaternary Agilent 1100 Series HPLC system. A fully automated 10-step chromatography run was carried out. Each full MS scan (400-1600 m/z) was followed by five data-dependent MS/MS scans. The number of the micro scans was set to 1 both for MS and MS/MS. The settings were as follows: repeat count 2; repeat duration 30 s; exclusion list size 500 and exclusion duration 120 s, while the minimum signal threshold was set to 100. MS Data Processing: The MS/MS data set was searched using ProLuCID (v. 1.3.3) against 36628 non-redundant Homo sapiens proteins (downloaded from NCBI RefSeq 2016-06-10), 193 usual contaminants, and, to estimate false discovery rates (FDRs), 36821 randomized amino acid sequences derived from each NR protein. To account for alkylation by CAM, 57 Da were added statically to the cysteines. To account for oxidation, 16 Da were added as a differential modification to methionines. Peptide/spectrum matches were sorted and selected to an FDR less than 5% at the peptide and protein levels, using DTASelect in combination with swallow, an in-house software. [doi:10.25345/C5J629] [dataset license: CC0 1.0 Universal (CC0 1.0)]

Keywords: Mediator ; MED26 ; little elongation complex (LEC) ; Interactor of Little Elongation Complex ELL subunit 1 (ICE1)

Contact

Principal Investigators:
(in alphabetical order)
Laurence Florens, The Stowers Institute for Medical Research, USA
Submitting User: laflorens

Publications

Takahashi H, Ranjan A, Chen S, Suzuki H, Shibata M, Hirose T, Hirose H, Sasaki K, Abe R, Chen K, He Y, Zhang Y, Takigawa I, Tsukiyama T, Watanabe M, Fujii S, Iida M, Yamamoto J, Yamaguchi Y, Suzuki Y, Matsumoto M, Nakayama KI, Washburn MP, Saraf A, Florens L, Sato S, Tomomori-Sato C, Conaway RC, Conaway JW, Hatakeyama S.
The role of Mediator and Little Elongation Complex in transcription termination.
Nat Commun. 2020 Feb 26;11(1):1063. Epub 2020 Feb 26.

Number of Files:
Total Size:
Spectra:
Subscribers:
 
Owner Reanalyses
Experimental Design
    Conditions:
    Biological Replicates:
    Technical Replicates:
 
Identification Results
    Proteins (Human, Remapped):
    Proteins (Reported):
    Peptides:
    Variant Peptides:
    PSMs:
 
Quantification Results
    Differential Proteins:
    Quantified Proteins:
 
Browse Dataset Files Browse Results
 
FTP Download Link (click to copy):

- Dataset Reanalyses


+ Dataset History


Click here to queue conversion of this dataset's submitted spectrum files to open formats (e.g. mzML). This process may take some time.

When complete, the converted files will be available in the "ccms_peak" subdirectory of the dataset's FTP space (accessible via the "FTP Download" link to the right).
Number of distinct conditions across all analyses (original submission and reanalyses) associated with this dataset.

Distinct condition labels are counted across all files submitted in the "Metadata" category having a "Condition" column in this dataset.

"N/A" means no results of this type were submitted.
Number of distinct biological replicates across all analyses (original submission and reanalyses) associated with this dataset.

Distinct replicate labels are counted across all files submitted in the "Metadata" category having a "BioReplicate" or "Replicate" column in this dataset.

"N/A" means no results of this type were submitted.
Number of distinct technical replicates across all analyses (original submission and reanalyses) associated with this dataset.

The technical replicate count is defined as the maximum number of times any one distinct combination of condition and biological replicate was analyzed across all files submitted in the "Metadata" category. In the case of fractionated experiments, only the first fraction is considered.

"N/A" means no results of this type were submitted.
Originally identified proteins that were automatically remapped by MassIVE to proteins in the SwissProt human reference database.

"N/A" means no results of this type were submitted.
Number of distinct protein accessions reported across all analyses (original submission and reanalyses) associated with this dataset.

"N/A" means no results of this type were submitted.
Number of distinct unmodified peptide sequences reported across all analyses (original submission and reanalyses) associated with this dataset.

"N/A" means no results of this type were submitted.
Number of distinct peptide sequences (including modified variants or peptidoforms) reported across all analyses (original submission and reanalyses) associated with this dataset.

"N/A" means no results of this type were submitted.
Total number of peptide-spectrum matches (i.e. spectrum identifications) reported across all analyses (original submission and reanalyses) associated with this dataset.

"N/A" means no results of this type were submitted.
Number of distinct proteins quantified across all analyses (original submission and reanalyses) associated with this dataset.

Distinct protein accessions are counted across all files submitted in the "Statistical Analysis of Quantified Analytes" category having a "Protein" column in this dataset.

"N/A" means no results of this type were submitted.
Number of distinct proteins found to be differentially abundant in at least one comparison across all analyses (original submission and reanalyses) associated with this dataset.

A protein is differentially abundant if its change in abundance across conditions is found to be statistically significant with an adjusted p-value <= 0.05 and lists no issues associated with statistical tests for differential abundance.

Distinct protein accessions are counted across all files submitted in the "Statistical Analysis of Quantified Analytes" category having a "Protein" column in this dataset.

"N/A" means no results of this type were submitted.
This dataset may not contain all raw spectra data as originally deposited in PRIDE. It has been imported to MassIVE for reanalysis purposes, so its spectra data here may consist solely of processed peak lists suitable for reanalysis with most software.