scholarly journals Clustered, Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9-coupled Affinity Purification/Mass Spectrometry Analysis Revealed a Novel Role of Neurofibromin in mTOR Signaling

2017 ◽  
Vol 16 (4) ◽  
pp. 594-607 ◽  
Author(s):  
Xu Li ◽  
Min Gao ◽  
Jong Min Choi ◽  
Beom-Jun Kim ◽  
Mao-Tian Zhou ◽  
...  
2019 ◽  
Vol 10 (19) ◽  
pp. 5146-5155 ◽  
Author(s):  
Di Wu ◽  
Jingwen Li ◽  
Weston B. Struwe ◽  
Carol V. Robinson

A lectin affinity purification-mass spectrometry approach to characterize lectin-reactive glycoproteoforms and elucidate lectin specificities at the intact protein level.


2016 ◽  
Vol 7 (2) ◽  
pp. e2090-e2090 ◽  
Author(s):  
D Trisciuoglio ◽  
M Desideri ◽  
V Farini ◽  
T De Luca ◽  
M Di Martile ◽  
...  

2012 ◽  
Vol 198 (4) ◽  
pp. 623-636 ◽  
Author(s):  
Taras Makhnevych ◽  
Philip Wong ◽  
Oxana Pogoutse ◽  
Franco J. Vizeacoumar ◽  
Jack F. Greenblatt ◽  
...  

Systematic affinity purification combined with mass spectrometry analysis of N- and C-tagged cytoplasmic Hsp70/Hsp110 chaperones was used to identify new roles of Hsp70/Hsp110 in the cell. This allowed the mapping of a chaperone–protein network consisting of 1,227 unique interactions between the 9 chaperones and 473 proteins and highlighted roles for Hsp70/Hsp110 in 14 broad biological processes. Using this information, we uncovered an essential role for Hsp110 in spindle assembly and, more specifically, in modulating the activity of the widely conserved kinesin-5 motor Cin8. The role of Hsp110 Sse1 as a nucleotide exchange factor for the Hsp70 chaperones Ssa1/Ssa2 was found to be required for maintaining the proper distribution of kinesin-5 motors within the spindle, which was subsequently required for bipolar spindle assembly in S phase. These data suggest a model whereby the Hsp70–Hsp110 chaperone complex antagonizes Cin8 plus-end motility and prevents premature spindle elongation in S phase.


2021 ◽  
Author(s):  
Ching-Seng Ang ◽  
Joanna Sacharz ◽  
Michael G Leeming ◽  
Shuai Nie ◽  
Swati Varshney ◽  
...  

Co-immunoprecipitation of proteins coupled to mass spectrometry has transformed modern biology understanding of protein interaction networks. These approaches exploit the selective isolation of tagged proteins by affinity enrichment / purification to identify protein binding partners at scale and in an unbiased manner. In instances where a suitable antibody is not be available it is common to graft synthetic tags such as FLAG or His Tags onto target protein sequences allowing the use of commercially available and validated antibodies for affinity purification. To allow the selective elution of protein complexes competitive displacement using a large molar excess of the tag peptide is widely used. Yet, this creates downstream challenges for the mass spectrometry analysis due to the presence of large quantities of a contaminating peptide. Here, we demonstrate that Field Asymmetric Ion Mobility Spectrometry (FAIMS), a gas phase ion separation device can be applied to FLAG-Tag and His-Tag pull down assay to increase the depth of protein coverage in these experiments. By excluding tag peptides based on their ion mobility profiles we demonstrate that single compensation voltage, or stepped compensation voltages strategies can significantly increase the coverage of total proteins by up to 2.5-fold and unique proteins by up to 15-fold versus experiments that do not use FAIMS. Combined these results highlight FAIMS is able to improve proteome depth by excluding interfering peptides without the need for additional sample handling or altering sample preparation protocols.


Author(s):  
Malene E. Lindholm ◽  
David Jimenez-Morales ◽  
Han Zhu ◽  
Kinya Seo ◽  
David Amar ◽  
...  

Background: ACTN2 (alpha-actinin 2) anchors actin within cardiac sarcomeres. The mechanisms linking ACTN2 mutations to myocardial disease phenotypes are unknown. Here, we characterize patients with novel ACTN2 mutations to reveal insights into the physiological function of ACTN2. Methods: Patients harboring ACTN2 protein-truncating variants were identified using a custom mutation pipeline. In patient-derived iPSC-cardiomyocytes, we investigated transcriptional profiles using RNA sequencing, contractile properties using video-based edge detection, and cellular hypertrophy using immunohistochemistry. Structural changes were analyzed through electron microscopy. For mechanistic studies, we used coimmunoprecipitation for ACTN2, followed by mass-spectrometry to investigate protein-protein interaction, and protein tagging followed by confocal microscopy to investigate introduction of truncated ACTN2 into the sarcomeres. Results: Patient-derived iPSC-cardiomyocytes were hypertrophic, displayed sarcomeric structural disarray, impaired contractility, and aberrant Ca 2+ -signaling. In heterozygous indel cells, the truncated protein incorporates into cardiac sarcomeres, leading to aberrant Z-disc ultrastructure. In homozygous stop-gain cells, affinity-purification mass-spectrometry reveals an intricate ACTN2 interactome with sarcomere and sarcolemma-associated proteins. Loss of the C-terminus of ACTN2 disrupts interaction with ACTN1 and GJA1, 2 sarcolemma-associated proteins, which may contribute to the clinical arrhythmic and relaxation defects. The causality of the stop-gain mutation was verified using CRISPR-Cas9 gene editing. Conclusions: Together, these data advance our understanding of the role of ACTN2 in the human heart and establish recessive inheritance of ACTN2 truncation as causative of disease.


2014 ◽  
Vol 306 (9) ◽  
pp. C805-C818 ◽  
Author(s):  
Priyanka Kohli ◽  
Malte P. Bartram ◽  
Sandra Habbig ◽  
Caroline Pahmeyer ◽  
Tobias Lamkemeyer ◽  
...  

The function of an individual protein is typically defined by protein-protein interactions orchestrating the formation of large complexes critical for a wide variety of biological processes. Over the last decade the analysis of purified protein complexes by mass spectrometry became a key technique to identify protein-protein interactions. We present a fast and straightforward approach for analyses of interacting proteins combining a Flp-in single-copy cellular integration system and single-step affinity purification with single-shot mass spectrometry analysis. We applied this protocol to the analysis of the YAP and TAZ interactome. YAP and TAZ are the downstream effectors of the mammalian Hippo tumor suppressor pathway. Our study provides comprehensive interactomes for both YAP and TAZ and does not only confirm the majority of previously described interactors but, strikingly, revealed uncharacterized interaction partners that affect YAP/TAZ TEAD-dependent transcription. Among these newly identified candidates are Rassf8, thymopoetin, and the transcription factors CCAAT/enhancer-binding protein (C/EBP)β/δ and core-binding factor subunit β (Cbfb). In addition, our data allowed insights into complex stoichiometry and uncovered discrepancies between the YAP and TAZ interactomes. Taken together, the stringent approach presented here could help to significantly sharpen the understanding of protein-protein networks.


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