scholarly journals The C terminus of the nuclear protein NuMA: Phylogenetic distribution and structure

2009 ◽  
Vol 13 (10) ◽  
pp. 2573-2577 ◽  
Author(s):  
Patricia C. Abad ◽  
I. Saira Mian ◽  
Cedric Plachot ◽  
Aniysha Nelpurackal ◽  
Carol Bator-Kelly ◽  
...  
Development ◽  
1989 ◽  
Vol 106 (3) ◽  
pp. 611-617 ◽  
Author(s):  
A.H. Brivanlou ◽  
R.M. Harland

We have used a monoclonal antibody directed against the C-terminus of the Drosophila invected homeodomain to detect a nuclear protein in brain cells of Xenopus laevis embryos. We refer to this antigen as the Xenopus EN protein. The EN protein is localized at midneurula stage to a band of cells in the anterior portion of the neural plate, on each side of the neural groove. Later in development, the expression coincides with the boundary of the midbrain and hindbrain, and persists at least to the swimming tadpole stage. These properties make the EN protein an excellent molecular marker for anterior neural structures. In embryos where inductive interactions between mesodermal and ectodermal tissues have been perturbed, the expression of the EN protein is altered; in embryos that have been anterodorsalized by LiCl treatment, the region that expresses the EN protein is expanded, but still well organized. In ventralized UV-irradiated embryos, the absence of the protein is correlated with the absence of anterior neural structures. In extreme exogastrulae, where the contacts between head mesoderm and prospective neurectoderm are lost, the EN protein is not expressed.


1994 ◽  
Vol 14 (12) ◽  
pp. 8399-8407 ◽  
Author(s):  
J Flach ◽  
M Bossie ◽  
J Vogel ◽  
A Corbett ◽  
T Jinks ◽  
...  

RNA-binding proteins have been suggested to move in association with RNA as it leaves the nucleus. The NPL3 gene of the yeast Saccharomyces cerevisiae encodes in nuclear protein with consensus RNA-binding motifs and similarity to heterogeneous nuclear ribonucleoproteins and members of the S/R protein family. We show that although Npl3 is located in the nucleus, it can shuttle between nuclei in yeast heterokaryons. In contrast, other nucleus-targeted proteins do not leave the nucleus under similar conditions. Mutants missing the RNA-binding motifs or the N terminus are still capable of shuttling in and out of the nucleus. Npl3 mutants missing the C terminus fail to localize to the nucleus. Overproduction of Npl3 in wild-type cells shows cell growth. This toxicity depends on the presence of series of unique repeats in the N terminus and localization to the nucleus. We suggest that the properties of Npl3 are consistent with it being involved in export of RNAs from the nucleus.


2008 ◽  
Vol 55 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Joanna Lesicka-Górecka ◽  
Bogna Szarzyńska ◽  
Marta Sawczak ◽  
Ivona Bagdiul ◽  
Paweł Górski ◽  
...  

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.


1994 ◽  
Vol 14 (12) ◽  
pp. 8399-8407
Author(s):  
J Flach ◽  
M Bossie ◽  
J Vogel ◽  
A Corbett ◽  
T Jinks ◽  
...  

RNA-binding proteins have been suggested to move in association with RNA as it leaves the nucleus. The NPL3 gene of the yeast Saccharomyces cerevisiae encodes in nuclear protein with consensus RNA-binding motifs and similarity to heterogeneous nuclear ribonucleoproteins and members of the S/R protein family. We show that although Npl3 is located in the nucleus, it can shuttle between nuclei in yeast heterokaryons. In contrast, other nucleus-targeted proteins do not leave the nucleus under similar conditions. Mutants missing the RNA-binding motifs or the N terminus are still capable of shuttling in and out of the nucleus. Npl3 mutants missing the C terminus fail to localize to the nucleus. Overproduction of Npl3 in wild-type cells shows cell growth. This toxicity depends on the presence of series of unique repeats in the N terminus and localization to the nucleus. We suggest that the properties of Npl3 are consistent with it being involved in export of RNAs from the nucleus.


Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 159-173 ◽  
Author(s):  
M K Nelson ◽  
T Kurihara ◽  
P A Silver

Abstract Mutations in the SEC63 gene of Saccharomyces cerevisiae affect both nuclear protein localization and translocation of proteins into the endoplasmic reticulum. We now report the isolation of suppressors of sec63-101 (formerly npl1-1), a temperature-sensitive allele of SEC63. Five complementation groups of extragenic mutations, son1-son5 (suppressor of npl1-1), were identified among the recessive suppressors. The son mutations are specific to SEC63, are not bypass suppressors, and are not new alleles of previously identified secretory (SEC61, SEC62, KAR2) or nuclear protein localization genes (NPL3, NPL4, NPL6). son1 mutations show regional specificity of suppression of sec63 alleles. At low temperatures, son1 mutants grow slowly and show partial mislocalization of nuclear antigens. The SON1 gene maps to chromosome IV and encodes a nuclear protein of 531 amino acids that contains two acidic stretches and a putative nuclear localization sequence. We show that son1 mutations suppress sec63-101 by elimination of Son1p function.


Author(s):  
Ichiro Yamamoto ◽  
Toshiaki Tachibana ◽  
Hiroko Maruyama ◽  
Noriyuki Komatsu ◽  
Hiroyuki Kuramoto ◽  
...  

We have paid attention to the alteration of glycosyltransferase in carcinoma cells, because it might be related to the malignancy of the cells. In this connection, localization of β1-4 galactosyl transferase (β1-4 Gal T) in human endometrial carcinoma cells was examined immunocytochemically using two kinds of cell lines, each of which showed different degree of differentiation.An antibody was purified from the rabbit antiserum against the synthetic peptide, IFNRLVFRGMSC (W89) of human β1-4 Gal T coupled with KLH (keyhole limpet hemocyanine) by protein A column and peptide-affinity column chromatography. The anti-W89 serum reacts to the C-terminus of human β 1-4 Gal T and to both membrane-bound and soluble forms of the enzyme. Cell line of well differentiated endometrial adenocarcinoma (I) and that of poorly differentiated endometrial adenocarcinoma (50B) were cultivated respectively in MEM medium containing 15% FCS and 2 mM glutamine for 4 d at 37°C under 5% CO2. The cells were fixed in a mixture of 4% paraformaldehyde and 0.1% glutaraldehyde in 0.1 M Soerensen’s phosphate buffer (pH 7.4) at 4°C for 30 min, washed with PBS, then freezed and thawed. The indirect method of the peroxidase- labeled antibody technique was used for immunocytochemistry of both LM and TEM on the cell lines. The cells were dehydrated in ethanol and embedded in TAAB 812. Ultrathin sections were observed under a TEM, JEM-100S.


2020 ◽  
Vol 477 (1) ◽  
pp. 173-189 ◽  
Author(s):  
Marco Pedretti ◽  
Carolina Conter ◽  
Paola Dominici ◽  
Alessandra Astegno

Arabidopsis centrin 2, also known as calmodulin-like protein 19 (CML19), is a member of the EF-hand superfamily of calcium (Ca2+)-binding proteins. In addition to the notion that CML19 interacts with the nucleotide excision repair protein RAD4, CML19 was suggested to be a component of the transcription export complex 2 (TREX-2) by interacting with SAC3B. However, the molecular determinants of this interaction have remained largely unknown. Herein, we identified a CML19-binding site within the C-terminus of SAC3B and characterized the binding properties of the corresponding 26-residue peptide (SAC3Bp), which exhibits the hydrophobic triad centrin-binding motif in a reversed orientation (I8W4W1). Using a combination of spectroscopic and calorimetric experiments, we shed light on the SAC3Bp–CML19 complex structure in solution. We demonstrated that the peptide interacts not only with Ca2+-saturated CML19, but also with apo-CML19 to form a protein–peptide complex with a 1 : 1 stoichiometry. Both interactions involve hydrophobic and electrostatic contributions and include the burial of Trp residues of SAC3Bp. However, the peptide likely assumes different conformations upon binding to apo-CML19 or Ca2+-CML19. Importantly, the peptide dramatically increases the affinity for Ca2+ of CML19, especially of the C-lobe, suggesting that in vivo the protein would be Ca2+-saturated and bound to SAC3B even at resting Ca2+-levels. Our results, providing direct evidence that Arabidopsis SAC3B is a CML19 target and proposing that CML19 can bind to SAC3B through its C-lobe independent of a Ca2+ stimulus, support a functional role for these proteins in TREX-2 complex and mRNA export.


2005 ◽  
Vol 41 ◽  
pp. 15-30 ◽  
Author(s):  
Helen C. Ardley ◽  
Philip A. Robinson

The selectivity of the ubiquitin–26 S proteasome system (UPS) for a particular substrate protein relies on the interaction between a ubiquitin-conjugating enzyme (E2, of which a cell contains relatively few) and a ubiquitin–protein ligase (E3, of which there are possibly hundreds). Post-translational modifications of the protein substrate, such as phosphorylation or hydroxylation, are often required prior to its selection. In this way, the precise spatio-temporal targeting and degradation of a given substrate can be achieved. The E3s are a large, diverse group of proteins, characterized by one of several defining motifs. These include a HECT (homologous to E6-associated protein C-terminus), RING (really interesting new gene) or U-box (a modified RING motif without the full complement of Zn2+-binding ligands) domain. Whereas HECT E3s have a direct role in catalysis during ubiquitination, RING and U-box E3s facilitate protein ubiquitination. These latter two E3 types act as adaptor-like molecules. They bring an E2 and a substrate into sufficiently close proximity to promote the substrate's ubiquitination. Although many RING-type E3s, such as MDM2 (murine double minute clone 2 oncoprotein) and c-Cbl, can apparently act alone, others are found as components of much larger multi-protein complexes, such as the anaphase-promoting complex. Taken together, these multifaceted properties and interactions enable E3s to provide a powerful, and specific, mechanism for protein clearance within all cells of eukaryotic organisms. The importance of E3s is highlighted by the number of normal cellular processes they regulate, and the number of diseases associated with their loss of function or inappropriate targeting.


1993 ◽  
Vol 70 (03) ◽  
pp. 454-457 ◽  
Author(s):  
Claus Bregengaard ◽  
Ole Nordfang ◽  
Per Østergaard ◽  
Jens G L Petersen ◽  
Giorgio Meyn ◽  
...  

SummaryTissue factor pathway inhibitor (TFPI) is a feed back inhibitor of the initial activation of the extrinsic pathway of coagulation. In humans, injection of heparin results in a 2-6 fold increase in plasma TFPI and recent studies suggest that TFPI may be important for the anticoagulant activity of heparin. Full length (FL) TFPI, but not recombinant two-domain (2D) TFPI, has a poly cationic C-terminus showing very strong heparin binding. Therefore, we have investigated if heparin affects the pharmacokinetics of TFPI with and without this C-terminus.FL-TFPI (608 U/kg) and 2D-TFPI (337 U/kg) were injected intravenously in rabbits with and without simultaneous intravenous injections of low molecular weight heparin (450 anti-XaU/kg).Heparin decreased the volume of distribution and the clearance of FL-TFPI by a factor 10-15, whereas the pharmacokinetics of 2D-TFPI were unaffected by heparin. When heparin was administered 2 h following TFPI the recovery of FL-TFPI was similar to that found in the group receiving the two compounds simultaneously, suggesting that the releasable pool of FL-TFPI is removed very slowly in the absence of circulating heparin.


1993 ◽  
Vol 69 (05) ◽  
pp. 485-489 ◽  
Author(s):  
Isabelle Djaffar ◽  
Didier Vilette ◽  
Dominique Pidard ◽  
Jean-Luc Wautier ◽  
Jean-Philippe Rosa

SummaryThe human platelet antigen (HPA) 3 system is expressed on GPIIb, one subunit of GPIIb-IIIa, the platelet fibrinogen receptor. It was recently shown that HPA-3 was associated with an Ile843/Ser polymorphism. To investigate further HPA-3 determinant structure, we localized an HPA-3a determinant, recognized by the alloantiserum Leka, within the last 29 amino acids of GPIIbα. This region encompasses the polymorphic Ile843, which, as expected, is substituted into Ser in Leka-negative individuals, as shown by DNA sequence after polymerase chain reaction on platelet RNA. In addition, contribution of glycosylation to the determinant structure was demonstrated since the Leka antigenicity was strongly decreased after specifically removing nonterminal O-linked sugars, but not terminal sialic acids. We have thus refined the localization of an HPA-3a determinant within the last 29 amino acids, including Ile843, of GPIIb heavy chain, and shown that the Leka HPA-3a determinant is dependent, in part, upon the serine-linked carbohydrates adjacent to Ile/Ser843.


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