scholarly journals KLP38B: A Mitotic Kinesin-related Protein That Binds PP1

1997 ◽  
Vol 138 (2) ◽  
pp. 395-409 ◽  
Author(s):  
Luke Alphey ◽  
Louise Parker ◽  
Gillian Hawcroft ◽  
Yiquan Guo ◽  
Kim Kaiser ◽  
...  
Keyword(s):  
Chromatin Condensation ◽  
Related Protein ◽  
Proliferating Cells ◽  
Direct Binding ◽  
Kinesin Superfamily ◽  
Partial Redundancy ◽  
Related Proteins ◽  
First Time

We have identified a new member of the kinesin superfamily in Drosophila, KLP38B (kinesin-like protein at 38B). KLP38B was isolated through its two-hybrid interaction with the catalytic subunit of type 1 serine/threonine phosphoprotein phosphatase (PP1). We demonstrate that recombinant KLP38B and PP1 associate in vitro. This is the first demonstration of direct binding of a kinesin-related protein to a regulatory enzyme. Though most closely related to the Unc-104 subfamily of kinesin-related proteins, KLP38B is expressed only in proliferating cells. KLP38B mutants show cell proliferation defects in many tissues. KLP38B is required for normal chromatin condensation as embryos from KLP38B mutant mothers have undercondensed chromatin at metaphase and anaphase. This is the first time that a kinesin-related protein has been shown to have such a role. Incomplete lethality of a strong KLP38B allele suggests partial redundancy with one or more additional kinesin-related proteins.

scholarly journals DSK1, a novel kinesin-related protein from the diatom Cylindrotheca fusiformis that is involved in anaphase spindle elongation.

1996 ◽  
Vol 133 (3) ◽  
pp. 595-604 ◽  
Author(s):  
H Wein ◽  
M Foss ◽  
B Brady ◽  
W Z Cande
Keyword(s):  
Mitotic Spindle ◽  
Related Protein ◽  
Cylindrotheca Fusiformis ◽  
Peptide Antibody ◽  
Spindle Midzone ◽  
Conserved Region ◽  
Spindle Elongation ◽  
Kinesin Superfamily ◽  
Related Proteins

We have identified an 80-kD protein that is involved in mitotic spindle elongation in the diatom Cylindrotheca fusiformis. DSK1 (Diatom Spindle Kinesin 1) was isolated using a peptide antibody raised against a conserved region in the motor domain of the kinesin superfamily. By sequence homology, DSK1 belongs to the central motor family of kinesin-related proteins. Immunoblots using an antibody raised against a non-conserved region of DSK1 show that DSK1 is greatly enriched in mitotic spindle preparations. Anti-DSK1 stains in diatom central spindle with a bias toward the midzone, and staining is retained in the spindle midzone during spindle elongation in vitro. Furthermore, preincubation with anti-DSK1 blocks function in an in vitro spindle elongation assay. This inhibition of spindle elongation can be rescued by preincubating concurrently with the fusion protein against which anti-DSK1 was raised. We conclude that DSK1 is involved in spindle elongation and is likely to be responsible for pushing hal-spindles apart in the spindle midzone.

Continuous Ketone Monitoring: A New Paradigm for Physiologic Monitoring

2021 ◽  
pp. 193229682110098
Author(s):  
Jennifer Y. Zhang ◽  
Trisha Shang ◽  
Suneil K. Koliwad ◽  
David C. Klonoff
Keyword(s):  
Interstitial Fluid ◽  
Good Accuracy ◽  
Physiologic Monitoring ◽  
New Paradigm ◽  
Continuous Glucose Monitor ◽  
Sensor Platform ◽  
Wired Enzyme ◽  
First Time

In this issue of JDST, Alva and colleagues present for the first time, development of a continuous ketone monitor (CKM) tested both in vitro and in humans. Their sensor measured betahydroxybutyrate (BHB) in interstitial fluid (ISF). The sensor was based on wired enzyme electrochemistry technology using BHB dehydrogenase. The sensor required only a single retrospective calibration without a need for further adjustments over 14 days. The device produced a linear response over the 0-8 mM range with good accuracy. This novel CKM could provide a new dimension of useful automatically collected information for managing diabetes. Passively collected ISF ketone information would be useful for predicting and managing ketoacidosis in patients with type 1 diabetes, as well as other states of abnormal ketonemia. Although additional studies of this CKM will be required to assess performance in intended patient populations and prospective factory calibration will be required to support real time measurements, this novel monitor has the potential to greatly improve outcomes for people with diabetes. In the future, a CKM might be integrated with a continuous glucose monitor in the same sensor platform.

scholarly journals Direct In Vitro Binding of Full-Length Human Immunodeficiency Virus Type 1 Nef Protein to CD4 Cytoplasmic Domain

2001 ◽  
Vol 75 (8) ◽  
pp. 3960-3964 ◽  
Author(s):  
Andrea Preusser ◽  
Lars Briese ◽  
Andreas S. Baur ◽  
Dieter Willbold
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Human Immunodeficiency Virus ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Immunodeficiency Virus ◽  
N Terminus ◽  
Human Immunodeficiency Viruses ◽  
Direct Binding

ABSTRACT The Nef protein of the simian and human immunodeficiency viruses is known to directly bind and downregulate the CD4 receptor. Although the molecular mechanism is well understood, direct binding of Nef and CD4 is difficult to demonstrate and is believed to be of low affinity. Applying nuclear magnetic resonance and fluorescence spectroscopy, we biophysically reevaluated the CD4-Nef complex and found the dissociation constant to be in the submicromolar range. We conclude that additional, so far disregarded residues in the N terminus of Nef are important for interaction with CD4.

scholarly journals Development of a Cell-Based Assay Probing the Specific Interaction between the Human Immunodeficiency Virus Type 1 Nucleocapsid and Psi RNA In Vivo

2007 ◽  
Vol 81 (11) ◽  
pp. 6151-6155 ◽  
Author(s):  
Soo In Jang ◽  
Young Ho Kim ◽  
Soon Young Paik ◽  
Ji Chang You
Keyword(s):  
Human Immunodeficiency Virus ◽  
Specific Interaction ◽  
Deletion Mapping ◽  
Packaging Signal ◽  
Immunodeficiency Virus ◽  
A Cell ◽  
First Time

ABSTRACT Here, we describe a cell-based in vivo assay that probes the specific interaction between nucleocapsid (NC) protein and Psi (Ψ) RNA, the human immunodeficiency virus (HIV) packaging signal. The results demonstrate for the first time a specific NC-Ψ interaction within living cells. The specificity and applicability of the assay were confirmed by mutational studies of NC and deletion-mapping analyses of Ψ-RNA as well as by testing the in vivo NC-binding effects of NC-aptamer RNAs identified previously in vitro. This assay system would facilitate further detailed studies of the NC-Ψ interaction in vivo and the screening of various anti-HIV molecules targeting NC and the specific interaction.

scholarly journals Isoliquiritigenin prevents hyperglycemia-induced renal injuries by inhibiting inflammation and oxidative stress via SIRT1-dependent mechanism

2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Xiaozhong Huang ◽  
Yujuan Shi ◽  
Hongjin Chen ◽  
Rongrong Le ◽  
Xiaohua Gong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
In Vitro Models ◽  
Sirtuin 1 ◽  
Health Concern ◽  
Flavonoid Compound ◽  
Direct Binding ◽  
And Oxidative Stress

AbstractDiabetic nephropathy (DN) as a global health concern is closely related to inflammation and oxidation. Isoliquiritigenin (ISL), a natural flavonoid compound, has been demonstrated to inhibit inflammation in macrophages. Herein, we investigated the effect of ISL in protecting against the injury in STZ-induced type 1 DN and in high glucose-induced NRK-52E cells. In this study, it was revealed that the administration of ISL not only ameliorated renal fibrosis and apoptosis, but also induced the deterioration of renal function in diabetic mice. Mediated by MAPKs and Nrf-2 signaling pathways, respectively, upstream inflammatory response and oxidative stress were neutralized by ISL in vitro and in vivo. Moreover, as further revealed by the results of molecular docking, sirtuin 1 (SIRT1) binds to ISL directly, and the involvement of SIRT1 in ISL-mediated renoprotective effects was confirmed by studies using in vitro models of SIRT1 overexpression and knockdown. In summary, by reducing inflammation and oxidative stress, ISL has a significant pharmacological effect on the deterioration of DN. The benefits of ISL are associated with the direct binding to SIRT1, the inhibition of MAPK activation, and the induction of Nrf-2 signaling, suggesting the potential of ISL for DN treatment.

scholarly journals In Vitro and In Vivo Characterization of a Pigeon Paramyxovirus Type 1 Isolated from Domestic Pigeons in Victoria, Australia 2011

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 429
Author(s):  
Songhua Shan ◽  
Kerri Bruce ◽  
Vittoria Stevens ◽  
Frank Wong ◽  
Jianning Wang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Fusion Gene ◽  
Chicken Embryo Fibroblast ◽  
Haemagglutination Inhibition ◽  
Clinical Signs ◽  
First Time ◽  
Domestic Pigeons

Significant mortalities of racing pigeons occurred in Australia in late 2011 associated with a pigeon paramyxovirus serotype 1 (PPMV-1) infection. The causative agent, designated APMV-1/pigeon/Australia/3/2011 (P/Aus/3/11), was isolated from diagnostic specimens in specific pathogen free (SPF) embryonated eggs and was identified by a Newcastle Disease virus (NDV)-specific RT-PCR and haemagglutination inhibition (HI) test using reference polyclonal antiserum specific for NDV. The P/Aus/3/11 strain was further classified as PPMV-1 using the HI test and monoclonal antibody 617/161 by HI and phylogenetic analysis of the fusion gene sequence. The isolate P/Aus/3/11 had a slow haemagglutin-elution rate and was inactivated within 45 min at 56 °C. Cross HI tests generated an R value of 0.25, indicating a significant antigenic difference between P/Aus/3/11 and NDV V4 isolates. The mean death time (MDT) of SPF eggs infected with the P/Aus/3/11 isolate was 89.2 hr, characteristic of a mesogenic pathotype, consistent with other PPMV-1 strains. The plaque size of the P/Aus/3/11 isolate on chicken embryo fibroblast (CEF) cells was smaller than those of mesogenic and velogenic NDV reference strains, indicating a lower virulence phenotype in vitro and challenge of six-week-old SPF chickens did not induce clinical signs. However, sequence analysis of the fusion protein cleavage site demonstrated an 112RRQKRF117 motif, which is typical of a velogenic NDV pathotype. Phylogenetic analysis indicated that the P/Aus/3/11 isolate belongs to a distinct subgenotype within class II genotype VI of avian paramyxovirus type 1. This is the first time this genotype has been detected in Australia causing disease in domestic pigeons and is the first time since 2002 that an NDV with potential for virulence has been detected in Australia.

scholarly journals Two Caenorhabditis elegans calponin-related proteins have overlapping functions to maintain cytoskeletal integrity and are essential for reproduction

2020 ◽  
Author(s):  
Shoichiro Ono ◽  
Kanako Ono
Keyword(s):  
Caenorhabditis Elegans ◽  
Actin Filaments ◽  
Body Wall ◽  
The Body ◽  
Body Wall Muscle ◽  
Related Protein ◽  
Somatic Gonad ◽  
Related Proteins

AbstractMulticellular organisms have multiple genes encoding calponins and calponin-related proteins, and some of these are known to regulate actin cytoskeletal dynamics and contractility. However, functional similarities and differences among these proteins are largely unknown. In the nematode Caenorhabditis elegans, UNC-87 is a calponin-related protein with seven calponin-like (CLIK) motifs and is required for maintenance of contractile apparatuses in muscle cells. Here, we report that CLIK-1, another calponin-related protein that also contains seven CLIK motifs, has an overlapping function with UNC-87 to maintain actin cytoskeletal integrity in vivo and has both common and different actin-regulatory activities in vitro. CLIK-1 is predominantly expressed in the body wall muscle and somatic gonad, where UNC-87 is also expressed. unc-87 mutation causes cytoskeletal defects in the body wall muscle and somatic gonad, whereas clik-1 depletion alone causes no detectable phenotypes. However, simultaneous depletion of clik-1 and unc-87 caused sterility due to ovulation failure by severely affecting the contractile actin networks in the myoepithelial sheath of the somatic gonad. In vitro, UNC-87 bundles actin filaments. However, CLIK-1 binds to actin filaments without bundling them and is antagonistic to UNC-87 in filament bundling. UNC-87 and CLIK-1 share common functions to inhibit cofilin binding and allow tropomyosin binding to actin filaments, suggesting that both proteins stabilize actin filaments. Thus, partially redundant functions of UNC-87 and CLIK-1 in ovulation is likely mediated by their common actin-regulatory activities, but their distinct activities in actin bundling suggest that they also have different biological functions.

scholarly journals Dysregulation of splicing-related proteins in prostate cancer is controlled by FOXA1

2018 ◽  
Author(s):  
John G. Foster ◽  
Rebecca Arkell ◽  
Marco Del Giudice ◽  
Chinedu Anene ◽  
Andrea Lauria ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Patient Outcomes ◽  
Transcriptional Networks ◽  
Over Expression ◽  
Castration Resistant ◽  
Related Proteins ◽  
First Time

AbstractProstate cancer (PCa) is genomically driven by dysregulation of transcriptional networks involving the transcriptional factors (TFs) FOXA1, ERG, AR, and HOXB13. However, the role of these specific TFs in the regulation of alternative pre-mRNA splicing (AS), which is a proven therapeutic vulnerability for cancers driven by the TF MYC, is not described. Using transcriptomic datasets from PCa patients, we tested for an association between expression of FOXA1, ERG, AR, HOXB13, and MYC, and genes involved in AS - termed splicing-related proteins (SRPs), which have pleiotropic roles in RNA metabolism. We identified FOXA1 as the strongest predictor of dysregulated SRP gene expression, which was associated with PCa disease relapse after treatment. Subsequently, we selected a subset of FOXA1-binding and actively-transcribed SRP genes that phenocopy the FOXA1 dependency of PCa cells, and confirmed in vitro via knockdown and over-expression that FOXA1 regulates SRP gene expression. Finally, we demonstrated the persistence of a FOXA1-SRP gene association in treatment-relapsed castration-resistant PCa (CRPCa) patients. Our data demonstrate, for the first time, that FOXA1 controls dysregulated SRP gene expression, which is associated with poor PCa patient outcomes. Analogous to MYC-driven cancers, our findings implicate the therapeutic targeting of SRPs and AS in FOXA1-overexpressing PCa.

scholarly journals Ebosin Ameliorates Psoriasis-Like Inflammation of Mice via miR-155 Targeting tnfaip3 on IL-17 Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Weiwei Guo ◽  
Fengying Xu ◽  
Zhuochen Zhuang ◽  
Zhe Liu ◽  
Jiming Xie ◽  
...  
Keyword(s):  
Signs And Symptoms ◽  
Skin Lesions ◽  
Epidermal Differentiation ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Psoriatic Skin ◽  
Direct Binding ◽  
Related Proteins

Psoriasis is a recurrent autoimmune skin disease with aberrant regulation of keratinocytes and immunocytes. There is no universally accepted single treatment available for psoriasis, and the establishment of a common treatment option to control its signs and symptoms is urgently needed. Here, we found Ebosin, a novel exopolysaccharide isolated from Streptomyces sp. 139 by our lab, not only could ameliorate inflammation in LPS-induced keratinocytes through IKK/NF-kapaB pathway, but also attenuate psoriatic skin lesions and reduce inflammatory factors expression in imiquimod (IMQ)-mediated psoriatic mice. Except for inhibiting the expression of epidermal differentiation related proteins, Ebosin significantly increased the percentage of CD4+Foxp3+CD25+ Tregs and decreased CD4+IL17A+ Th17 cells in psoriatic mice. Furthermore, we demonstrate that Ebosin significantly suppressed the IL-17 signaling pathway via A20 (encoded by tnfaip3) in vivo. As the direct binding of tnfaip3 to miR-155 has been demonstrated by luciferase reporter assay, and Ebosin has been demonstrated to inhibit miR-155 level in vitro and in vivo, our study first indicates that Ebosin reduces inflammation through the miR-155-tnfaip3-IL-17 axis and T cell differentiation in a psoriasis-like model. Thus, we conclude that Ebosin can act as a promising therapeutic candidate for the treatment of psoriasis.

scholarly journals The Leishmania infantum cytosolic SIR2-related protein 1 (LiSIR2RP1) is an NAD+-dependent deacetylase and ADP-ribosyltransferase

2008 ◽  
Vol 415 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Joana Tavares ◽  
Ali Ouaissi ◽  
Nuno Santarém ◽  
Denis Sereno ◽  
Baptiste Vergnes ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Catalytic Domain ◽  
Insoluble Fraction ◽  
Related Protein ◽  
Targeted Disruption ◽  
Gene Encoding ◽  
Adp Ribosyltransferase ◽  
First Time

Proteins of the SIR2 (Silent Information Regulator 2) family are characterized by a conserved catalytic domain that exerts unique NAD+-dependent deacetylase activity on histones and various other cellular substrates. Previous reports from us have identified a Leishmania infantum gene encoding a cytosolic protein termed LiSIR2RP1 (Leishmania infantum SIR2-related protein 1) that belongs to the SIR2 family. Targeted disruption of one LiSIR2RP1 gene allele led to decreased amastigote virulence, in vitro as well as in vivo. In the present study, attempts were made for the first time to explore and characterize the enzymatic functions of LiSIR2RP1. The LiSIR2RP1 exhibited robust NAD+-dependent deacetylase and ADP-ribosyltransferase activities. Moreover, LiSIR2RP1 is capable of deacetylating tubulin, either in dimers or, when present, in taxol-stabilized microtubules or in promastigote and amastigote extracts. Furthermore, the immunostaining of parasites revealed a partial co-localization of α-tubulin and LiSIR2RP1 with punctate labelling, seen on the periphery of both promastigote and amastigote stages. Isolated parasite cytoskeleton reacted with antibodies showed that part of LiSIR2RP1 is associated to the cytoskeleton network of both promastigote and amastigote forms. Moreover, the Western blot analysis of the soluble and insoluble fractions of the detergent of promastigote and amastigote forms revealed the presence of α-tubulin in the insoluble fraction, and the LiSIR2RP1 distributed in both soluble and insoluble fractions of promastigotes as well as amastigotes. Collectively, the results of the present study demonstrate that LiSIR2RP1 is an NAD+-dependent deacetylase that also exerts an ADP-ribosyltransferase activity. The fact that tubulin could be among the targets of LiSIR2RP1 may have significant implications during the remodelling of the morphology of the parasite and its interaction with the host cell.

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