Systematic screening for palmitoyl transferase activity of the DHHC protein family in mammalian cells

Methods ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Yuko Fukata ◽  
Tsuyoshi Iwanaga ◽  
Masaki Fukata
Keyword(s):  
Mammalian Cells ◽  
Protein Family ◽  
Transferase Activity ◽  
Systematic Screening ◽  
Dhhc Protein

scholarly journals DHHC protein family targets different subsets of glioma stem cells in specific niches

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Xueran Chen ◽  
Lei Hu ◽  
Haoran Yang ◽  
Huihui Ma ◽  
Kaiqin Ye ◽  
...  
Keyword(s):  
Stem Cells ◽  
Protein Family ◽  
Glioma Stem Cells ◽  
Dhhc Protein

Functional characterisation of the YIPF protein family in mammalian cells

2016 ◽  
Vol 147 (4) ◽  
pp. 439-451 ◽  
Author(s):  
Tilen Kranjc ◽  
Eugene Dempsey ◽  
Gerard Cagney ◽  
Nobuhiro Nakamura ◽  
Denis C. Shields ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Protein Family ◽  
Functional Characterisation

S-acylation by the DHHC protein family

2010 ◽  
Vol 38 (2) ◽  
pp. 522-524 ◽  
Author(s):  
Jennifer Greaves ◽  
Luke H. Chamberlain
Keyword(s):  
Substrate Specificity ◽  
Protein S ◽  
Protein Family ◽  
Target Proteins ◽  
Dhhc Protein

A family of 23 DHHC (Asp-His-His-Cys) proteins that function as mammalian S-acyltransferases has been identified, reinvigorating the study of protein S-acylation. Recent studies have continued to reveal how S-acylation affects target proteins, and have provided glimpses of how DHHC-substrate specificity might be achieved.

scholarly journals Electroporated recombinant proteins as tools for in vivo functional complementation, imaging and chemical biology

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Amal Alex ◽  
Valentina Piano ◽  
Soumitra Polley ◽  
Marchel Stuiver ◽  
Stephanie Voss ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Mammalian Cells ◽  
Cellular Localization ◽  
Mitotic Checkpoint ◽  
Transferase Activity ◽  
Checkpoint Signaling ◽  
Chemically Modified ◽  
Promising Tool

Delivery of native or chemically modified recombinant proteins into mammalian cells shows promise for functional investigations and various technological applications, but concerns that sub-cellular localization and functional integrity of delivered proteins may be affected remain high. Here, we surveyed batch electroporation as a delivery tool for single polypeptides and multi-subunit protein assemblies of the kinetochore, a spatially confined and well-studied subcellular structure. After electroporation into human cells, recombinant fluorescent Ndc80 and Mis12 multi-subunit complexes exhibited native localization, physically interacted with endogenous binding partners, and functionally complemented depleted endogenous counterparts to promote mitotic checkpoint signaling and chromosome segregation. Farnesylation is required for kinetochore localization of the Dynein adaptor Spindly. In cells with chronically inhibited farnesyl transferase activity, in vitro farnesylation and electroporation of recombinant Spindly faithfully resulted in robust kinetochore localization. Our data show that electroporation is well-suited to deliver synthetic and chemically modified versions of functional proteins, and, therefore, constitutes a promising tool for applications in chemical and synthetic biology.

scholarly journals The Coxiella burnetii Ankyrin Repeat Domain-Containing Protein Family Is Heterogeneous, with C-Terminal Truncations That Influence Dot/Icm-Mediated Secretion

2009 ◽  
Vol 191 (13) ◽  
pp. 4232-4242 ◽  
Author(s):  
Daniel E. Voth ◽  
Dale Howe ◽  
Paul A. Beare ◽  
Joseph P. Vogel ◽  
Nathan Unsworth ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Coxiella Burnetii ◽  
Legionella Pneumophila ◽  
Mammalian Cells ◽  
Q Fever ◽  
Parasitophorous Vacuole ◽  
Protein Family ◽  
Ankyrin Repeat ◽  
Reference Isolate ◽  
Type Iv

ABSTRACT Coxiella burnetii is an obligate intracellular bacterium that directs biogenesis of a parasitophorous vacuole (PV) for replication. Effectors of PV maturation are likely translocated into the host cytosol by a type IV secretion system (T4SS) with homology to the Dot/Icm apparatus of Legionella pneumophila. Since secreted bacterial virulence factors often functionally mimic the activities of host proteins, prokaryotic proteins with eukaryotic features are considered candidate T4SS substrates. Genes encoding proteins with eukaryotic-type ankyrin repeat domains (Anks) were identified upon genome sequencing of the C. burnetii Nine Mile reference isolate, which is associated with a case of human acute Q fever. Interestingly, recent genome sequencing of the G and K isolates, derived from human chronic endocarditis patients, and of the Dugway rodent isolate revealed remarkable heterogeneity in the Ank gene family, with the Dugway isolate harboring the largest number of full-length Ank genes. Using L. pneumophila as a surrogate host, we identified 10 Dugway Anks and 1 Ank specific to the G and K endocarditis isolates translocated into the host cytosol in a Dot/Icm-dependent fashion. A 10-amino-acid C-terminal region appeared to be necessary for translocation, with some Anks also requiring the chaperone IcmS for secretion. Ectopically expressed Anks localized to a variety of subcellular regions in mammalian cells, including microtubules, mitochondria, and the PV membrane. Collectively, these data suggest that C. burnetii isolates translocate distinct subsets of the Ank protein family into the host cytosol, where they modulate diverse functions, some of which may be unique to C. burnetii pathotypes.

scholarly journals The structure of an ABC toxin particle determined by X-ray crystallography and single particle EM.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1825-C1825
Author(s):  
Jason Busby ◽  
Santosh Panjikar ◽  
Michael Landsberg ◽  
Mark Hurst ◽  
Shaun Lott
Keyword(s):  
Single Particle ◽  
Mammalian Cells ◽  
Hollow Structure ◽  
Protein Family ◽  
Terminal Region ◽  
C Protein ◽  
X Ray ◽  
X Ray Crystallography ◽  
Toxin Complex ◽  
C Proteins

The ABC toxin complexes produced by certain bacteria are of interest owing to their potent insecticidal activity and potential role in human disease. These complexes comprise at least three proteins (A, B and C), which must assemble to be fully toxic. The carboxy-terminal region of the C protein is the main cytotoxic component, and is poorly conserved between different toxin complexes. A general model of action has been proposed, in which the toxin complex binds to the cell surface via the A protein, is endocytosed, and sub-sequently forms a pH-triggered channel, allowing the translocation of C into the cytoplasm, where it can cause cytoskeletal disruption in both insect and mammalian cells. We have determined the three-dimensional structure of the complex formed between the B and C proteins by X-ray crystallography to 2.5Å. These proteins assemble to form an unprecedented, large hollow structure that encapsulates and sequesters the cytotoxic, C-terminal region of the C protein like the shell of an egg. The shell is decorated on one end by a β-propeller domain, which mediates attachment of the B–C heterodimer to the A protein in the native complex. The structure reveals how C auto-proteolyses when folded in complex with B. The C protein is the first example of a structure that contains rearrangement hotspot (RHS) repeats, and illustrates a striking structural architecture that we predict to be conserved across both this widely distributed bacterial protein family and the related eukaryotic tyrosine-aspartate (YD)-repeat-containing protein family, which includes the teneurins. The structure provides the first clues about the function of these protein repeat families, and suggests a generic mechanism for protein encapsulation and delivery. We have been able to model the complete ABC toxin complex for the by docking the B–C complex and both associated chitinase enzymes, Chi1 and Chi2, onto the single-particle electron microscopy structure of the Y. entomophaga A pentamer. The structure of the complete complex presented here reveals how the cytotoxic C proteins of ABC-type toxin complexes are processed and protected, demonstrates the function of the B protein within the complex and provides a framework for further experiments to build a complete mechanistic model of action for this class of toxins. More broadly, it also illuminates the function of the widely distributed RHS- and YD-repeat families of proteins, which had previously been unknown.

scholarly journals DEAD-box protein family member DDX28 is a negative regulator of HIF-2α and eIF4E2-directed hypoxic translation

2019 ◽  
Author(s):  
Sonia L. Evagelou ◽  
Olivia Bebenek ◽  
Erin J. Specker ◽  
James Uniacke
Keyword(s):  
Family Member ◽  
Mammalian Cells ◽  
Protein Family ◽  
Negative Regulator ◽  
Protein Levels ◽  
Oxygen Homeostasis ◽  
Dead Box ◽  
Nuclear Abundance ◽  
Potential Tumor Suppressor ◽  
Proliferative Advantage

ABSTRACTHypoxia occurs when there is a deficiency in oxygen delivery to tissues and is connected to physiological and pathophysiological processes such as embryonic development, wound healing, heart disease and cancer. The master regulators of oxygen homeostasis in mammalian cells are the heterodimeric hypoxia-inducible transcription factors HIF-1 and HIF-2. The oxygen-labile HIF-2α subunit has not only been implicated in transcription, but also as a regulator of eIF4E2-directed hypoxic translation. Here, we have identified the DEAD-box protein family member DDX28 as a novel interactor and negative regulator of HIF-2α that suppresses its ability to activate eIF4E2-directed translation. We demonstrate that stable silencing of DDX28 via shRNA in hypoxic human U87MG glioblastoma cells caused an increase, relative to control, to: HIF-2α protein levels, the ability of eIF4E2 to bind the m7GTP cap structure, and the translation of select eIF4E2 target mRNAs. DDX28 depletion elevated both nuclear and cytoplasmic HIF-2α, but HIF-2α transcriptional activity did not increase possibly due to its already high nuclear abundance in hypoxic control cells. Depletion of DDX28 conferred a proliferative advantage to hypoxic, but not normoxic cells, which is likely a consequence of the translational upregulation of a subset of hypoxia-response mRNAs. DDX28 protein levels are reduced in several cancers, including glioma, relative to normal tissue. Therefore, we uncover a regulatory mechanism for this potential tumor suppressor in the repression of HIF-2α- and eIF4E2-mediated translation activation of oncogenic mRNAs.

scholarly journals The Evolutionary Conserved Transmembrane BAX Inhibitor Motif (TMBIM) Containing Protein Family Members 5 and 6 Are Essential for the Development and Survival of Drosophila melanogaster

2021 ◽  
Vol 9 ◽  
Author(s):  
Li Zhang ◽  
Sebastian Buhr ◽  
Aaron Voigt ◽  
Axel Methner
Keyword(s):  
Drosophila Melanogaster ◽  
Mammalian Cells ◽  
Developmental Stages ◽  
Family Members ◽  
Protein Family ◽  
Expression Levels ◽  
Atp Production ◽  
Evolutionarily Conserved ◽  
Human Proteins ◽  
Er Calcium

The mammalian Transmembrane BAX Inhibitor Motif (TMBIM) protein family consists of six evolutionarily conserved hydrophobic proteins that affect programmed cell death and the regulation of intracellular calcium levels. The bacterial ortholog BsYetJ is a pH-dependent calcium channel. We here identified seven TMBIM family members in Drosophila melanogaster and describe their expression levels in diverse tissues and developmental stages. A phylogenetic analysis revealed that CG30379 represents the ortholog of human TMBIM4 although these two proteins are much less related than TMBIM5 (CG2076 and CG1287/Mics1) and TMBIM6 (CG7188/Bi-1) to their respective orthologs. For TMBIM1-3 the assignment is more dubious because the fly and the human proteins cluster together. We conducted a functional analysis based on expression levels and the availability of RNAi lines. This revealed that the ubiquitous knockdown of CG3798/Nmda1 and CG3814/Lfg had no effect on development while knockdown of CG2076/dTmbim5 resulted in death at the pupa stage and knockdown of CG7188/dTmbim6 in death at the embryonic stage. Ubiquitous knockdown of the second TMBIM5 paralog CG1287/Mics1 ensued in male sterility. Knockdown of dTmbim5 and 6 in muscle and neural tissue also greatly reduced lifespan through different mechanisms. Knockdown of the mitochondrial family member dTmbim5 resulted in reduced ATP production and a pro-apoptotic expression profile while knockdown of the ER protein dTmbim6 increased the ER calcium levels similar to findings in mammalian cells. Our data demonstrate that dTmbim5 and 6 are essential for fly development and survival but affect cell survival through different mechanisms.

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