scholarly journals The GCP3-Interacting Proteins GIP1 and GIP2 Are Required for γ-Tubulin Complex Protein Localization, Spindle Integrity, and Chromosomal Stability

2012 ◽  
Vol 24 (3) ◽  
pp. 1171-1187 ◽  
Author(s):  
Natacha Janski ◽  
Kinda Masoud ◽  
Morgane Batzenschlager ◽  
Etienne Herzog ◽  
Jean-Luc Evrard ◽  
...  
Keyword(s):  
Protein Localization ◽  
Interacting Proteins ◽  
Chromosomal Stability ◽  
Complex Protein

scholarly journals Epstein-Barr virus LMP1 modulates the CD63 interactome

2021 ◽  
Author(s):  
Mujeeb Cheerathodi ◽  
Dingani Nkosi ◽  
Allaura S. Cone ◽  
Sara B. York ◽  
David G. Meckes Jr.
Keyword(s):  
Intracellular Signaling ◽  
Ribosomal Proteins ◽  
Protein Localization ◽  
Cell Communication ◽  
Enrichment Analysis ◽  
Surface Proteins ◽  
Rab Gtpases ◽  
Interacting Proteins ◽  
Sorting Nexins ◽  
Cargo Sorting

Abstract Tetraspanin CD63 is a cluster of cell surface proteins with four transmembrane domains which associates with tetraspanin-enriched microdomains and typically localizes to late endosomes and lysosomes. CD63 plays an important role in cellular trafficking of different proteins, EV cargo sorting and vesicles formation. We have preciously shown that CD63 is important in LMP1 trafficking to EVs and this also affects LMP1 mediated intracellular signaling including MAPK/ERK, NF-κB and mTOR activation. Using the BioID combined with mass spectrometry, we sought to define the broad CD63 interactome and how LMP1 modulates this network of interacting proteins. We identified a total of 1600 total proteins as proximal interacting newtwork of proteins to CD63. Biological process enrichment analysis revealed significant involvement in signal transduction, cell communication, protein metabolism and transportation. The CD63 only interactome was enriched in Rab GTPases, SNARE proteins and sorting nexins while adding LMP1 into the interactome increased presence of signaling and ribosomal proteins. Our results showed that LMP1 alters the CD63 interactome, shifting the network of proteins enrichment from protein localization and vesicle mediated transportation to metabolic processes and translation. We also show that LMP1 interacts with mTor, Nedd4L and PP2A indicating formation of a multiprotein complex with CD63 thereby potentially regulating LMP1 dependent mTor signaling. Collectively, the comprehensive analysis of CD63 proximal interacting proteins provides insights into network of partners required for endocytic trafficking, extracellular vesicle cargo sorting, formation and secretion.

scholarly journals Identification of intracellular glycosaminoglycan-interacting proteins by affinity purification mass spectrometry

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Henning Großkopf ◽  
Sarah Vogel ◽  
Claudia Damaris Müller ◽  
Sebastian Köhling ◽  
Jan-Niklas Dürig ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Mechanisms ◽  
Protein Localization ◽  
Affinity Purification ◽  
Intracellular Localization ◽  
Enrichment Analysis ◽  
Transport Processes ◽  
Interacting Proteins ◽  
Affinity Purification Mass Spectrometry ◽  
Functional Components

Abstract Glycosaminoglycans (GAGs) are essential functional components of the extracellular matrix (ECM). Artificial GAGs like sulfated hyaluronan (sHA) exhibit pro-osteogenic properties and boost healing processes. Hence, they are of high interest for supporting bone regeneration and wound healing. Although sulfated GAGs (sGAGs) appear intracellularly, the knowledge about intracellular effects and putative interaction partners is scarce. Here we used an affinity-purification mass spectrometry-based (AP-MS) approach to identify novel and particularly intracellular sGAG-interacting proteins in human bone marrow stromal cells (hBMSC). Overall, 477 proteins were found interacting with at least one of four distinct sGAGs. Enrichment analysis for protein localization showed that mainly intracellular and cell-associated interacting proteins were identified. The interaction of sGAG with α2-macroglobulin receptor-associated protein (LRPAP1), exportin-1 (XPO1), and serine protease HTRA1 (HTRA1) was confirmed in reverse assays. Consecutive pathway and cluster analysis led to the identification of biological processes, namely processes involving binding and processing of nucleic acids, LRP1-dependent endocytosis, and exosome formation. Respecting the preferentially intracellular localization of sGAG in vesicle-like structures, also the interaction data indicate sGAG-specific modulation of vesicle-based transport processes. By identifying many sGAG-specific interacting proteins, our data provide a resource for upcoming studies aimed at molecular mechanisms and understanding of sGAG cellular effects.

Development of Ubiquitin Tools for Studies of Complex Ubiquitin Processing Protein Machines

2020 ◽  
Vol 23 (23) ◽  
pp. 2614-2625
Author(s):  
Xin Sui ◽  
Yi-Ming Li
Keyword(s):  
Protein Localization ◽  
The Other ◽  
Related Protein ◽  
Deubiquitinating Enzymes ◽  
Post Translational Modifications ◽  
Physiological Processes ◽  
Complex Protein ◽  
Recombinant Technology ◽  
Functional Mechanisms

: Ubiquitination is one of the most extensive post-translational modifications in eukaryotes and is involved in various physiological processes such as protein degradation, autophagy, protein interaction, and protein localization. The ubiquitin (Ub)-related protein machines include Ub-activating enzymes (E1s), Ub-conjugating enzymes (E2s), Ub ligases (E3s), deubiquitinating enzymes (DUBs), p97, and the proteasomes. In recent years, the role of DUBs has been extensively studied and relatively well understood. On the other hand, the functional mechanisms of the other more complex ubiquitin-processing protein machines (e.g., E3, p97, and proteasomes) are still to be sufficiently well explored due to their intricate nature. One of the hurdles facing the studies of these complex protein machines is the challenge of developing tailor-designed structurally defined model substrates, which unfortunately cannot be directly obtained using recombinant technology. Consequently, the acquisition and synthesis of the ubiquitin tool molecules are essential for the elucidation of the functions and structures of the complex ubiquitin-processing protein machines. This paper aims to highlight recent studies on these protein machines based on the synthetic ubiquitin tool molecules.

The Golgi complex of Saccharomyces cerevisiae

1995 ◽  
Vol 73 (S1) ◽  
pp. 343-346 ◽  
Author(s):  
Vladimir Krasnov ◽  
Todd R. Graham
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Golgi Complex ◽  
Posttranslational Modification ◽  
Mammalian Cells ◽  
Secretory Pathway ◽  
Protein Transport ◽  
Protein Localization ◽  
Model System ◽  
Complex Protein ◽  
Golgi Protein

The Golgi complex of Saccharomyces cerevisiae is required for protein transport, posttranslational modification, and sorting within the secretory pathway. Only in the last few years has it become clear that these events are functionally organized into distinct Golgi compartments analagous to the cis–trans compartments of the plant and animal Golgi complex. The mechanisms by which the Golgi complex maintains its own organization and complement of intrinsic enzymes against the flow of lipid and protein through the secretory pathway are still poorly understood. However, studies using Saccharomyces cerevisiae as a model system are providing insights into mechanisms of Golgi protein localization that appear to be conserved between yeast and mammalian cells. This review describes the structure and organization of the yeast Golgi complex and recent work towards defining localization signals within intrinsic enzymes of this organelle. Key words: Golgi complex, protein sorting, Saccharomyces cerevisiae, α-1,3-mannosyltransferase.

scholarly journals Arabidopsis MZT1 homologs GIP1 and GIP2 are essential for centromere architecture

2015 ◽  
Vol 112 (28) ◽  
pp. 8656-8660 ◽  
Author(s):  
Morgane Batzenschlager ◽  
Inna Lermontova ◽  
Veit Schubert ◽  
Jörg Fuchs ◽  
Alexandre Berr ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Histone H3 ◽  
Genome Integrity ◽  
Interacting Proteins ◽  
Central Function ◽  
Chromatid Cohesion ◽  
Histone H3 Variant ◽  
Complex Protein ◽  
Cohesin Subunit

Centromeres play a pivotal role in maintaining genome integrity by facilitating the recruitment of kinetochore and sister-chromatid cohesion proteins, both required for correct chromosome segregation. Centromeres are epigenetically specified by the presence of the histone H3 variant (CENH3). In this study, we investigate the role of the highly conserved γ-tubulin complex protein 3-interacting proteins (GIPs) in Arabidopsis centromere regulation. We show that GIPs form a complex with CENH3 in cycling cells. GIP depletion in the gip1gip2 knockdown mutant leads to a decreased CENH3 level at centromeres, despite a higher level of Mis18BP1/KNL2 present at both centromeric and ectopic sites. We thus postulate that GIPs are required to ensure CENH3 deposition and/or maintenance at centromeres. In addition, the recruitment at the centromere of other proteins such as the CENP-C kinetochore component and the cohesin subunit SMC3 is impaired in gip1gip2. These defects in centromere architecture result in aneuploidy due to severely altered centromeric cohesion. Altogether, we ascribe a central function to GIPs for the proper recruitment and/or stabilization of centromeric proteins essential in the specification of the centromere identity, as well as for centromeric cohesion in somatic cells.

scholarly journals Epstein-Barr Virus LMP1 Modulates the CD63 Interactome

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 675
Author(s):  
Mujeeb Cheerathodi ◽  
Dingani Nkosi ◽  
Allaura S. Cone ◽  
Sara B. York ◽  
David G. Meckes
Keyword(s):  
Intracellular Signaling ◽  
Ribosomal Proteins ◽  
Protein Localization ◽  
Cell Communication ◽  
Enrichment Analysis ◽  
Surface Proteins ◽  
Rab Gtpases ◽  
Interacting Proteins ◽  
Sorting Nexins ◽  
Cargo Sorting

Tetraspanin CD63 is a cluster of cell surface proteins with four transmembrane domains; it is associated with tetraspanin-enriched microdomains and typically localizes to late endosomes and lysosomes. CD63 plays an important role in the cellular trafficking of different proteins, EV cargo sorting, and vesicle formation. We have previously shown that CD63 is important in LMP1 trafficking to EVs, and this also affects LMP1-mediated intracellular signaling including MAPK/ERK, NF-κB, and mTOR activation. Using the BioID method combined with mass spectrometry, we sought to define the broad CD63 interactome and how LMP1 modulates this network of interacting proteins. We identified a total of 1600 total proteins as a network of proximal interacting proteins to CD63. Biological process enrichment analysis revealed significant involvement in signal transduction, cell communication, protein metabolism, and transportation. The CD63-only interactome was enriched in Rab GTPases, SNARE proteins, and sorting nexins, while adding LMP1 into the interactome increased the presence of signaling and ribosomal proteins. Our results showed that LMP1 alters the CD63 interactome, shifting the network of protein enrichment from protein localization and vesicle-mediated transportation to metabolic processes and translation. We also show that LMP1 interacts with mTOR, Nedd4 L, and PP2A, indicating the formation of a multiprotein complex with CD63, thereby potentially regulating LMP1-dependent mTOR signaling. Collectively, the comprehensive analysis of CD63 proximal interacting proteins provides insights into the network of partners required for endocytic trafficking and extracellular vesicle cargo sorting, formation, and secretion.

scholarly journals Peptide Signals Encode Protein Localization

2007 ◽  
Vol 189 (21) ◽  
pp. 7581-7585 ◽  
Author(s):  
Jay H. Russell ◽  
Kenneth C. Keiler
Keyword(s):  
Protein Interactions ◽  
Fluorescent Protein ◽  
Protein Localization ◽  
Protein Protein Interactions ◽  
Helical Structures ◽  
Bacterial Proteins ◽  
Complex Protein ◽  
Peptide Signals ◽  
Green Fluorescent ◽  
Localization Information

ABSTRACT Many bacterial proteins are localized to precise intracellular locations, but in most cases the mechanism for encoding localization information is not known. Screening libraries of peptides fused to green fluorescent protein identified sequences that directed the protein to helical structures or to midcell. These peptides indicate that protein localization can be encoded in 20-amino-acid peptides instead of complex protein-protein interactions and raise the possibility that the location of a protein within the cell could be predicted from bioinformatic data.

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