scholarly journals Study of the structure and function of the HURP protein during mitotic division

2013 ◽  
Author(s):  
Κωνσταντίνος Νάκος
Keyword(s):  
Dna Binding ◽  
Xenopus Laevis ◽  
Histone Deacetylase ◽  
Dna Binding Protein ◽  
Mitotic Division ◽  
Structure And Function ◽  
Aurora A ◽  
Nucleosome Remodeling ◽  
And Function

Η πρωτεΐνη HURP (Hepatoma Up-Regulated protein) έχει αναγνωριστεί ως παράγονταςσυναρμολόγησης της ατράκτου (SAF) που ρυθμίζεται από τη RanGTP. Αρχικά βρέθηκε σε μιτωτικάεκχυλίσματα αυγών Xenopus laevis, σε σύμπλοκο με τις TPX2, XMAP215, Eg5 και Aurora A. Η HURPπροσδένεται στους μικροσωληνίσκους, εντοπίζεται κυρίως στους μικροσωληνίσκους των κινητοχώρωνκαι είναι απαραίτητη για την σωστή συναρμολόγηση της μιτωτικής ατράκτου. Παρόλο αυτά, πρωτεΐνεςπου αλληλεπιδρούν με τη HURP σε ανθρώπινα κύτταρα παραμένουν άγνωστες.Σε αυτή τη μελέτη περιγράφουμε την αναγνώριση μίας νέας πρωτεΐνης που αλληλεπιδρά με τη HURP,τη CHD4 (Chromodomain Helicase DNA binding protein 4) μία ATPάση της αναδιαμόρφωσης τηςχρωματίνης και καταλυτική υπομονάδα του συμπλόκου αποκετυλασών που ευθύνεται για τηναναδιαμόρφωση του νουκλεοσώματος (Nucleosome remodeling and histone Deacetylase - NuRD).Πρόσφατα η πρωτεΐνη CHD4 αναγνωρίστηκε ως πρωτεΐνη που προσδένεται στους μικροσωληνίσκουςκαι ρυθμίζεται από την RanGTP.Οι μελέτες μας σε ανθρώπινα κύτταρα έδειξαν ότι η CHD4 κατά τη μίτωση απελευθερώνεται από ταμιτωτικά χρωμοσώματα και εντοπίζεται στην άτρακτο, υποδεικνύοντας ένα καινούριο ρόλο της CHD4στη συναρμολόγηση της ατράκτου. Για να κατανοήσουμε τη λειτουργία της CHD4 πραγματοποιήσαμεμελέτες απαλοιφής της CHD4 με την τεχνική της αποσιώπισης γονιδίου με siRNA. Μείωση της CHD4προκαλεί βλάβες στη συναρμολόγηση της μιτωτικής ατράκτου και στη στοίχιση των χρωμοσωμάτωνστις αρχές της μίτωσης, οδηγώντας σε ανώμαλο διαχωρισμό των χρωμοσωμάτων. Επιπλέον, ηαπώλεια της CHD4 επηρρεάζει τη σταθερότητα των K-fibers μειώνοντας σημαντικά την ποσότητα των μικροσωληνίσκων των κινητοχώρων. Μετά την απαλοιφή της CHD4, ο εντοπισμός της HURP βρέθηκενα αλλάζει, χάνοντας την προτίμησή της για τους μικροσωληνίσκους, των κινητοχώρων,υποδεικνύοντας την πιθανή ρύθμιση του εντοπισμού της HURP από την CHD4. Τέλος από in vitro καιin vivo πειράματα, βρήκαμε ότι η CHD4 αλληλεπιδρά με τη μιτωτική κινάση Aurora A και την πρωτεΐνηTPX2 που συνδέεται με μικροσωληνίσκους, δημιουργώντας ένα καινούριο σύμπλοκο σημαντικό για τηλειτουργία της μιτωτικής ατράκτου στα κύτταρα θηλαστικών.

scholarly journals A DNA-binding protein is required for termination of transcription by RNA polymerase I in Xenopus laevis.

1990 ◽  
Vol 10 (6) ◽  
pp. 2793-2800 ◽  
Author(s):  
B McStay ◽  
R H Reeder
Keyword(s):  
Dna Binding ◽  
Xenopus Laevis ◽  
Rna Polymerase ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
In Vitro Transcription ◽  
Rna Polymerase I ◽  
Polymerase I ◽  
Terminator Sequence

We describe a partially fractionated in vitro transcription system from Xenopus laevis for the assay of transcription termination by RNA polymerase I. Termination in vitro was found to require a specific terminator sequence in the DNA and a DNA-binding protein fraction that produces a footprint over the terminator sequence.

Structure and function of the dioxin receptor: A DNA-binding protein similar to steroid hormone receptors

Chemosphere ◽  
1987 ◽  
Vol 16 (8-9) ◽  
pp. 1681-1686
Author(s):  
Lorenz Poellinger ◽  
Anna Wilhelmsson ◽  
Scott Cuthill ◽  
Johan Lund ◽  
Peter Söderkvist ◽  
...  
Keyword(s):  
Dna Binding ◽  
Hormone Receptors ◽  
Binding Protein ◽  
Steroid Hormone ◽  
Dna Binding Protein ◽  
Structure And Function ◽  
Steroid Hormone Receptors ◽  
And Function ◽  
Dioxin Receptor

scholarly journals Structure and function of phage p2 ORF34p2, a new type of single-stranded DNA binding protein

2009 ◽  
Vol 73 (6) ◽  
pp. 1156-1170 ◽  
Author(s):  
Erika Scaltriti ◽  
Mariella Tegoni ◽  
Claudio Rivetti ◽  
Hélène Launay ◽  
Jean-Yves Masson ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Structure And Function ◽  
Single Stranded Dna ◽  
New Type ◽  
And Function

A DNA-binding protein is required for termination of transcription by RNA polymerase I in Xenopus laevis

1990 ◽  
Vol 10 (6) ◽  
pp. 2793-2800
Author(s):  
B McStay ◽  
R H Reeder
Keyword(s):  
Dna Binding ◽  
Xenopus Laevis ◽  
Rna Polymerase ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
In Vitro Transcription ◽  
Rna Polymerase I ◽  
Polymerase I ◽  
Terminator Sequence

We describe a partially fractionated in vitro transcription system from Xenopus laevis for the assay of transcription termination by RNA polymerase I. Termination in vitro was found to require a specific terminator sequence in the DNA and a DNA-binding protein fraction that produces a footprint over the terminator sequence.

scholarly journals Sequence, Structure, and Function of DNA-Binding Protein in Deinococcus Wulumuqiensis R12

2021 ◽  
Author(s):  
Yao Chen ◽  
Zhihan Yang ◽  
Xue Zhou ◽  
Mengmeng Jin ◽  
Zijie Dai ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Envelope ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Proteomics Data ◽  
Oxidation Reduction ◽  
Oxidative Resistance ◽  
Dps Protein ◽  
And Function

Abstract Deinococcus wulumuqiensis R12, which was isolated from arid irradiated soil in Xinjiang province of China, belongs to a genus Deinococcus that is well-known for its extreme resistance to ionizing radiation and oxidative stress. The DNA-binding protein Dps has been studied for its great contribution to oxidative resistance. To explore the role of Dps in D. wulumuqiensis R12, the Dps sequence and homologous structure were analyzed. In addition, the dps gene was knocked out and proteomics was used to verify the functions of Dps in D. wulumuqiensis R12. Docking data and DNA binding experiments in vitro showed that the R12 Dps has a better DNA binding ability with the N-terminal than the R1 Dps1. When the dps gene was deleted in D. wulumuqiensis R12, its resistance to H2O2 and UV rays was greatly reduced, and the cell envelope was destroyed by H2O2 treatment. Additionally, the qRT-PCR and proteomics data suggested that when the dps gene was deleted, the catalase gene was significantly down-regulated in cells. And the proteomics data indicated the metabolism, transport and oxidation-reduction processes in D. wulumuqiensis R12 were down-regulated after the deletion of dps gene. Dps protein might play an important role in Deinococcus wulumuqiensis R12.

scholarly journals In Vitro Methylation of the Bsu RI (5′-GGCC-3′) Sites in the E2a Region of Adenovirus Type 2 DNA Does Not Affect Expression in Xenopus laevis Oocytes

1982 ◽  
Vol 2 (12) ◽  
pp. 1574-1580
Author(s):  
Lily Vardimon ◽  
Ursula Günthert ◽  
Walter Doerfler
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Dna Binding ◽  
Xenopus Laevis ◽  
Cell Lines ◽  
Control Region ◽  
Adenovirus Type ◽  
Dna Binding Protein

The early region 2a (E2a) of adenovirus type 2 (Ad2) DNA codes for a 72,000-dalton DNA-binding protein and is expressed in the Ad2-transformed hamster cell line HE1 but not in cell lines HE2 and HE3 (H. Esche, J. Virol. 41 :1076-1082, 1982; K. Johansson et al., J. Virol. 27 :628-639, 1978). An inverse correlation between DNA methylation at the 5′-CCGG-3′ sites of the E2a region and of gene expression in these cell lines has been observed (L. Vardimon et al., Nucleic Acids Res. 8 :2461-2473, 1980). When the cloned E2a region of Ad2 DNA is methylated in vitro at the 5′-CCGG-3′ sites, the gene is not transcribed after being injected into the nuclei of Xenopus laevis oocytes, whereas unmethylated DNA is expressed (L. Vardimon et al., Eur. J. Cell Biol. 25 :13-15, 1981; L. Vardimon et al., Proc. Natl. Acad. Sci. U.S.A. 79 :1073-1077, 1982). These data demonstrate that DNA methylation is directly involved in the shut-off of transcription. In the present communication we investigated in detail the control region of the gene for the DNA-binding protein in Ad2-transformed cell lines and showed that the first late control region (map coordinate 72 on the viral DNA) of the E2a region is present in its entirety in cell lines HE1, HE2, and HE3. The Hae III sites (5′-GGCC-3′) in the E2a region in all three cell lines were not methylated. When the DNA methyltransferase Bsu RI was used, all 5′-GGCC-3′ sites in the cloned E2a region of Ad2 DNA were methylated in vitro. It was shown that methylation of these sites did not inhibit the expression of this viral gene in X. laevis oocytes. Thus, for methylation to affect gene expression in the E2a region it has to occur at specific sites (e.g., 5′-CCGG-3′) which may be different for other genes.

Maintenance of Insect Ovarian Microtubular Structure and Function in vitro

1973 ◽  
Vol 242 (121) ◽  
pp. 253-254 ◽  
Author(s):  
H. STEBBINGS ◽  
N. A. RATCLIFFE
Keyword(s):  
Structure And Function ◽  
And Function
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