Self-interacting Domains in the C Terminus of a Cation-Cl-Cotransporter Described for the First Time

ABSTRACT Zac is a C2H2 zinc finger protein that regulates apoptosis and cell cycle arrest through DNA binding and transactivation. The coactivator proteins p300/CBP enhance transactivation through their histone acetyltransferase (HAT) activity by modulating chromatin structure. Here, we show that p300 increases Zac transactivation in a strictly HAT-dependent manner. Whereas the classic recruitment model proposes that coactivation simply depends on the capacity of the activator to recruit the coactivator, we demonstrate that coordinated binding of Zac zinc fingers and C terminus to p300 regulates HAT function by increasing histone and acetyl coenzyme A affinities and catalytic activity. This concerted regulation of HAT function is mediated via the KIX and CH3 domains of p300 in an interdependent manner. Interestingly, Zac zinc fingers 6 and 7 simultaneously play key roles in DNA binding and p300 regulation. Our findings demonstrate, for the first time, that C2H2 zinc fingers can link DNA binding to HAT signaling and suggest a dynamic role for DNA-binding proteins in the enzymatic control of transcription.

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Adenovirus Protein V Induces Redistribution of Nucleolin and B23 from Nucleolus to Cytoplasm

Journal of Virology ◽

10.1128/jvi.75.2.1031-1038.2001 ◽

2001 ◽

Vol 75 (2) ◽

pp. 1031-1038 ◽

Cited By ~ 82

Author(s):

David A. Matthews

Keyword(s):

Viral Infection ◽

Point Mutation ◽

Direct Effect ◽

Mutation Analysis ◽

Unique Property ◽

Adenovirus Infection ◽

C Terminus ◽

Infected Cells ◽

Synthesis And Processing ◽

First Time

ABSTRACT Adenovirus infection inhibits synthesis and processing of rRNA and redistributes nucleolar antigens. Adenovirus protein V associates with nucleoli in infected cells. This study delineates regions of protein V independently capable of nucleolar targeting. Also, evidence is presented that protein V has the unique property of relocating nucleolin and B23 to the cytoplasm when transiently expressed on its own in uninfected cells. Point mutation analysis indicates a role for the C terminus of protein V in the redirection of nucleolin and B23 to the cytoplasm. This is the first time an adenovirus protein has been shown to have a direct effect on nucleolar antigens in isolation from viral infection. Moreover, adenovirus protein V is the first protein demonstrated to be capable of redirecting nucleolin and B23 to the cytoplasm.

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C terminus of NisI provides specificity to nisin

Microbiology ◽

10.1099/mic.0.29083-0 ◽

2006 ◽

Vol 152 (12) ◽

pp. 3543-3549 ◽

Cited By ~ 26

Author(s):

Timo M. Takala ◽

Per E. J. Saris

Keyword(s):

Amino Acids ◽

Cell Membrane ◽

Specific Interaction ◽

Immunity Protein ◽

C Terminus ◽

Terminal Amino ◽

A Site ◽

Immunity Function ◽

First Time ◽

Deletion Series

Nisin-producing Lactococcus lactis protects its own cell membrane against the bacteriocin with the ABC transporter NisFEG, and the immunity lipoprotein NisI. In this study, in order to localize a site for specific nisin interaction in NisI, a C-terminal deletion series of NisI was constructed, and the C-terminally truncated NisI proteins were expressed in L. lactis. The shortest deletion (5 aa) decreased the nisin immunity capacity considerably in the nisin-negative strain MG1614, resulting in approximately 78 % loss of immunity function compared with native NisI. A deletion of 21 aa decreased the immunity level even more, but longer deletions, up to 74 aa, provided the same level of nisin immunity as the 21 aa deletion, i.e. approximately 14 % of the immunity provided by native NisI. Similar to native NisI, all the C-terminally truncated NisI proteins provided higher immunity to nisin in the NisFEG-expressing strain NZ9840 than in MG1614, i.e. approximately 40–50 % of the immunity capacity of native NisI. Then, it was determined whether the NisI C-terminal 21 aa fragment could protect cells against nisin. To target the 21 aa fragment to its natural location, 21 C-terminal amino acids from the subtilin-specific immunity lipoprotein SpaI were replaced by 21 C-terminal amino acids from NisI. The expression of the SpaI′–′NisI fusion in L. lactis strains significantly increased their nisin immunity. This is the first time the immunity function of a lantibiotic immunity protein has been transferred to another protein. However, unlike native NisI, and the C-terminally truncated NisI fragments, the increase in nisin immunity conferred by the SpaI′–′NisI fusion was the same in both the NisFEG strain NZ9840 and MG1614. In conclusion, the SpaI′–′NisI fusion could not enhance nisin immunity by interacting with NisFEG, whereas the C-terminally truncated NisI fragments and native NisI were able to enhance nisin immunity, probably by co-operation with NisFEG. The results made it evident that the C terminus of NisI is involved in specific interaction with nisin, and that it confers specificity for the NisI immunity lipoprotein.

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Domain Architecture of the Catalytic Subunit in the ISW2-Nucleosome Complex

Molecular and Cellular Biology ◽

10.1128/mcb.01351-07 ◽

2007 ◽

Vol 27 (23) ◽

pp. 8306-8317 ◽

Cited By ~ 82

Author(s):

Weiwei Dang ◽

Blaine Bartholomew

Keyword(s):

Chromatin Remodeling ◽

Cellular Differentiation ◽

Atp Hydrolysis ◽

Domain Architecture ◽

Catalytic Subunit ◽

Atpase Domain ◽

Entry Site ◽

Physical Connection ◽

C Terminus ◽

First Time

ABSTRACT ATP-dependent chromatin remodeling has an important role in the regulation of cellular differentiation and development. For the first time, a topological view of one of these complexes has been revealed, by mapping the interactions of the catalytic subunit Isw2 with nucleosomal and extranucleosomal DNA in the complex with all four subunits of ISW2 bound to nucleosomes. Different domains of Isw2 were shown to interact with the nucleosome near the dyad axis, another near the entry site of the nucleosome, and another with extranucleosomal DNA. The conserved DEXD or ATPase domain was found to contact the superhelical location 2 (SHL2) of the nucleosome, providing a direct physical connection of ATP hydrolysis with this region of nucleosomes. The C terminus of Isw2, comprising the SLIDE (SANT-like domain) and HAND domains, was found to be associated with extranucleosomal DNA and the entry site of nucleosomes. It is thus proposed that the C-terminal domains of Isw2 are involved in anchoring the complex to nucleosomes through their interactions with linker DNA and that they facilitate the movement of DNA along the surface of nucleosomes.

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Abscisic acid does not influence the subcellular distribution of the HYL1 protein from Arabidopsis thaliana.

Acta Biochimica Polonica ◽

10.18388/abp.2008_3058 ◽

2008 ◽

Vol 55 (3) ◽

pp. 517-524 ◽

Cited By ~ 1

Author(s):

Joanna Lesicka-Górecka ◽

Bogna Szarzyńska ◽

Marta Sawczak ◽

Ivona Bagdiul ◽

Paweł Górski ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Nuclear Protein ◽

Protein Localization ◽

Brassica Species ◽

Bioinformatic Analysis ◽

C Terminus ◽

Exact Function ◽

Protein Instability ◽

First Time ◽

Different Tissues

HYL1 is a nuclear protein involved in the processing of miRNAs but its exact function remains unknown. Arabidopsis thaliana hyl1 mutants exhibit hypersensitivity to ABA. We decided to answer the question whether ABA affects the HYL1 protein localization within the cell and show that it does not. We also studied the expression of HYL1 in different tissues and organs. In this paper we show for the first time the expression profile of the HYL1 protein using anti-HYL1 antibodies. The protein is present in seedlings and mature plants in all organs studied, with the highest amount in inflorescences. A. thaliana HYL1 protein has several repetitions of a 28-amino-acid sequence at the C-terminus that confer protein instability. Our bioinformatic analysis of HYL1 homologs in different Brassica species shows that this repetition is typical only for Arabidopsis. This may suggest a relatively late evolutionary acquisition of the C-terminal domain.

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The Histone H1-like protein AlgP facilitates even spacing of polyphosphate granules in Pseudomonas aeruginosa

10.1101/2021.08.24.457604 ◽

2021 ◽

Author(s):

Lisa Racki ◽

Ravi Chawla ◽

Steven Klupt ◽

Vadim Patsalo ◽

James Williamson

Keyword(s):

Pseudomonas Aeruginosa ◽

Functional Significance ◽

Critical Role ◽

Histone H1 ◽

Sequence Composition ◽

C Terminus ◽

Size Number ◽

Enrichment Protocol ◽

Opportunistic Human Pathogen ◽

First Time

Synthesis of polyphosphate (polyP) is an ancient and universal stress and starvation response in bacteria. In many bacteria, polyP chains come together to form granular superstructures within cells. Some species appear to regulate polyP granule subcellular organization. Despite the critical role of polyP in starvation fitness, the composition of these structures, mechanism(s) underpinning their organization, and functional significance of such organization are poorly understood. We previously determined that granules become transiently evenly spaced on the cell’s long axis during nitrogen starvation in the opportunistic human pathogen Pseudomonas aeruginosa>. Here, we developed a granule-enrichment protocol to screen for polyP granule-localizing proteins. We identified AlgP as a protein that associates with polyP granules. We further discovered that AlgP is required for the even spacing of polyP granules. AlgP is a DNA-binding protein with a 154 amino acid C-terminal domain enriched in ‘KPAA’ repeats and variants of this repeat, with an overall sequence composition similar to the C-terminal tail of eukaryotic histone H1. Granule size, number, and spacing are significantly perturbed in the absence of AlgP, or when AlgP is truncated to remove the C-terminus. The ΔalgP and algPΔCTD mutants having fewer, larger granules. We speculate that AlgP may contribute to spacing by tethering polyP granules to the chromosome, thereby inhibiting fusion with neighboring granules. Our discovery that AlgP facilitates granule spacing allows us for the first time to directly uncouple granule biogenesis from even spacing, and will inform future efforts to explore the functional significance of granule organization on fitness during starvation.

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Dependence on Myb expression is attenuated in myeloid leukaemia with N-terminal CEBPA mutations

Life Science Alliance ◽

10.26508/lsa.201800207 ◽

2019 ◽

Vol 2 (2) ◽

pp. e201800207 ◽

Cited By ~ 3

Author(s):

Giacomo Volpe ◽

Pierre Cauchy ◽

David S Walton ◽

Carl Ward ◽

Daniel Blakemore ◽

...

Keyword(s):

Myeloid Leukaemia ◽

Normal Karyotype ◽

Sequencing Data ◽

Mutational Status ◽

C Terminus ◽

Chromatin Immunoprecipitation Sequencing ◽

Cebpa Mutations ◽

First Time ◽

Do So

Mutations at the N- or C-terminus of C/EBPα are frequent in acute myeloid leukaemia (AML) with normal karyotype. Here, we investigate the role of the transcription factor Myb in AMLs driven by different combinations of CEBPA mutations. Using knockdown of Myb in murine cell lines modelling the spectrum of CEBPA mutations, we show that the effect of reduced Myb depends on the mutational status of the two Cebpa alleles. Importantly, Myb knockdown fails to override the block in myeloid differentiation in cells with biallelic N-terminal C/EBPα mutations, demonstrating for the first time that the dependency on Myb is much lower in AML with this mutational profile. By comparing gene expression following Myb knockdown and chromatin immunoprecipitation sequencing data for the binding of C/EBPα isoforms, we provide evidence for a functional cooperation between C/EBPα and Myb in the maintenance of AML. This co-dependency breaks down when both alleles of CEBPA harbour N-terminal mutations, as a subset of C/EBPα-regulated genes only bind the short p30 C/EBPα isoform and, unlike other C/EBPα-regulated genes, do so without a requirement for Myb.

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SUMOylome Modulates Intraflagellar Transport Machinery and Eukaryotic Cilia Motility

10.21203/rs.3.rs-132547/v1 ◽

2021 ◽

Author(s):

Komal Sharma ◽

Irina Sizova ◽

Girdhar Pandey ◽

Peter Hegemann ◽

Suneel Kateriya

Keyword(s):

Functional Role ◽

Intraflagellar Transport ◽

Small Gtpase ◽

The Other ◽

Signaling Proteins ◽

Sumoylation Site ◽

C Terminus ◽

First Time ◽

Insight Into

Abstract Translocation of channelrhodopsins (ChRs) is mediated by intraflagellar transport (IFT) machinery. However, the functional role of the network containing photoreceptors, IFT and other proteins in controlling cilia motility of the alga is still not fully delineated. In the current study, we identified two important motifs at the C-terminus of ChR1. One of them is similar to a known ciliary targeting sequence that specifically interacts with a small GTPase, and the other is a SUMOylation site. For the first time, experimental data provide an insight into the role of SUMOylation in the modulation of IFT & ChR1. Blocking of SUMOylation affected the phototaxis of C. reinhardtii cells. This implies SUMOylation based regulation of protein network controlling photomotility. The conservation of SUMOylation site pattern as analyzed for the relevant photoreceptors, IFT and its associated signaling proteins in other ciliated green algae suggested SUMOylation based photobehavioural response across the microbes. This report establishes a link between evolutionary conserved SUMOylation and ciliary machinery for the maintenance and functioning of cilia across the eukaryotes. Our enriched SUMOylome of C. reinhardtii comprehends the proteins related to ciliary development and, photo-signaling, along with homologue(s) associated to human ciliopathies as SUMO targets.

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Identification of the gene for disaggregatase fromMethanosarcina mazei

Archaea ◽

10.1155/2008/949458 ◽

2008 ◽

Vol 2 (3) ◽

pp. 185-191 ◽

Cited By ~ 3

Author(s):

Naoki Osumi ◽

Yoshihiro Kakehashi ◽

Shiho Matsumoto ◽

Kazunari Nagaoka ◽

Junichi Sakai ◽

...

Keyword(s):

Amino Acid ◽

Single Cells ◽

Pcr Analysis ◽

Amino Acid Residues ◽

Wall Function ◽

Rt Pcr ◽

Methanosarcina Mazei ◽

C Terminus ◽

First Time

The gene sequences encoding disaggregatase (Dag), the enzyme responsible for dispersion of cell aggregates ofMethanosarcina mazeito single cells, were determined for three strains ofM. mazei(S-6T, LYC and TMA). Thedaggenes of the three strains were 3234 bp in length and had almost the same sequences with 97% amino acid sequence identities. Dag was predicted to comprise 1077 amino acid residues and to have a molecular mass of 120 kDa containing three repeats of the DNRLRE domain in the C terminus, which is specific to the genusMethanosarcinaand may be responsible for structural organization and cell wall function. Recombinant Dag was overexpressed inEscherichia coliand preparations of the expressed protein exhibited enzymatic activity. The RT-PCR analysis showed thatdagwas transcribed to mRNA inM. mazeiLYC and indicated that the gene was expressed in vivo. This is the first time the gene involved in the morphological change ofMethanosarcinaspp. from aggregate to single cells has been identified.

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Unexpected Role for a Serine/Threonine-Rich Domain in the Candida albicans Iff Protein Family

Eukaryotic Cell ◽

10.1128/ec.05044-11 ◽

2011 ◽

Vol 10 (10) ◽

pp. 1317-1330 ◽

Cited By ~ 23

Author(s):

Anita Boisramé ◽

Amandine Cornu ◽

Grégory Da Costa ◽

Mathias L. Richard

Keyword(s):

Candida Albicans ◽

Cell Surface ◽

Protein Localization ◽

Protein Family ◽

Content Type ◽

Rich Domain ◽

C Terminus ◽

The Family ◽

Localization Signal ◽

First Time

ABSTRACTGlycosylphosphatidylinositol (GPI)-anchored proteins are an important class of cell wall proteins inCandida albicansbecause of their localization and their function, even if more than half of them have no characterized homolog in the databases. In this study, we focused on the IFF protein family, investigating their exposure on the cell surface and the sequences that determine their subcellular localization. Protein localization and surface exposure were monitored by the addition of a V5 tag on all members of the family. The data obtained using the complete proteins showed for Iff3 (or -9), Iff5, Iff6, and Iff8 a covalent linkage to the β-1,6-glucan network but, remarkably, showed that Iff2/Hyr3 was linked through disulfide bridges or NaOH-labile bonds. However, since some proteins of the Iff family were undetectable, we designed chimeric constructions using the last 60 amino acids of these proteins to test the localization signal. These constructions showed a β-1,6-glucan linkage for Iff1/Rbr3, Iff2/Hyr3, Iff4 and Iff7/Hyr4 C-terminal–Iff5 fusion proteins, and a membrane localization for the Iff10/Flo9 C terminus-Iff5 fusion protein. Immunofluorescence analyses coupled to these cell fraction data confirmed the importance of the length of the central serine/threonine-rich region for cell surface exposure. Further analysis of the Iff2/Hyr3 linkage to the cell surface showed for the first time that a serine/threonine central region of a GPI-anchored protein may be responsible for the disulfide and the NaOH bonds to the glucan and glycoproteins network and may also override the signal of the proximal ω site region.

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