scholarly journals Functional Characterization of the Adenylyl Cyclase Genesgs-1by Analysis of a Mutational Spectrum inCaenorhabditis elegans

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Celine Moorman ◽  
Ronald H A Plasterk
Keyword(s):  
Life Span ◽  
Adenylyl Cyclase ◽  
Neuronal Degeneration ◽  
Functional Characterization ◽  
Adenylyl Cyclases ◽  
Loss Of Function ◽  
C Elegans ◽  
Larval Stages ◽  
Pharyngeal Pumping

AbstractThe sgs-1 (suppressor of activated Gαs) gene encodes one of the four adenylyl cyclases in the nematode C. elegans and is most similar to mammalian adenylyl cyclase type IX. We isolated a complete loss-of-function mutation in sgs-1 and found it to result in animals with retarded development that arrest in variable larval stages. sgs-1 mutant animals exhibit lethargic movement and pharyngeal pumping and (while not reaching adulthood) have a mean life span that is >50% extended compared to wild type. An extensive set of reduction-of-function mutations in sgs-1 was isolated in a screen for suppressors of a neuronal degeneration phenotype induced by the expression of a constitutively active version of the heterotrimeric Gαs subunit of C. elegans. Although most of these mutations change conserved residues within the catalytic domains of sgs-1, mutations in the less-conserved transmembrane domains are also found. The sgs-1 reduction-of-function mutants are viable and have reduced locomotion rates, but do not show defects in pharyngeal pumping or life span.

scholarly journals Human xylosyltransferase I and N-terminal truncated forms: functional characterization of the core enzyme

2006 ◽  
Vol 394 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Sandra Müller ◽  
Jennifer Disse ◽  
Manuela Schöttler ◽  
Sylvia Schön ◽  
Christian Prante ◽  
...  
Keyword(s):  
Amino Acids ◽  
Catalytic Activity ◽  
Binding Capacity ◽  
Functional Characterization ◽  
Terminal Region ◽  
Binding Motif ◽  
Heparin Binding ◽  
Loss Of Function ◽  
The Impact

Human XT-I (xylosyltransferase I; EC 2.4.2.26) initiates the biosynthesis of the glycosaminoglycan linkage region and is a diagnostic marker of an enhanced proteoglycan biosynthesis. In the present study, we have investigated mutant enzymes of human XT-I and assessed the impact of the N-terminal region on the enzymatic activity. Soluble mutant enzymes of human XT-I with deletions at the N-terminal domain were expressed in insect cells and analysed for catalytic activity. As many as 260 amino acids could be truncated at the N-terminal region of the enzyme without affecting its catalytic activity. However, truncation of 266, 272 and 273 amino acids resulted in a 70, 90 and >98% loss in catalytic activity. Interestingly, deletion of the single 12 amino acid motif G261KEAISALSRAK272 leads to a loss-of-function XT-I mutant. This is in agreement with our findings analysing the importance of the Cys residues where we have shown that C276A mutation resulted in a nearly inactive XT-I enzyme. Moreover, we investigated the location of the heparin-binding site of human XT-I using the truncated mutants. Heparin binding was observed to be slightly altered in mutants lacking 289 or 568 amino acids, but deletion of the potential heparin-binding motif P721KKVFKI727 did not lead to a loss of heparin binding capacity. The effect of heparin or UDP on the XT-I activity of all mutants was not significantly different from that of the wild-type. Our study demonstrates that over 80% of the nucleotide sequence of the XT-I-cDNA is necessary for expressing a recombinant enzyme with full catalytic activity.

AmTAR2: Functional characterization of a honeybee tyramine receptor stimulating adenylyl cyclase activity

2017 ◽  
Vol 80 ◽  
pp. 91-100 ◽  
Author(s):  
Tina Reim ◽  
Sabine Balfanz ◽  
Arnd Baumann ◽  
Wolfgang Blenau ◽  
Markus Thamm ◽  
...  
Keyword(s):  
Adenylyl Cyclase ◽  
Functional Characterization ◽  
Cyclase Activity ◽  
Adenylyl Cyclase Activity

scholarly journals Molecular and functional characterization of detrusor PDGFRα positive cells in spinal cord injury-induced detrusor overactivity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ken Lee ◽  
Sang O Park ◽  
Pil-Cho Choi ◽  
Seung-Bum Ryoo ◽  
Haeyeong Lee ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Detrusor Overactivity ◽  
Ex Vivo ◽  
Functional Characterization ◽  
Interstitial Cells ◽  
Sk Channels ◽  
Loss Of Function ◽  
Cord Injury

AbstractVolume accommodation occurs via a novel mechanism involving interstitial cells in detrusor muscles. The interstitial cells in the bladder are PDGFRα+, and they restrain the excitability of smooth muscle at low levels and prevents the development of transient contractions (TCs). A common clinical manifestation of spinal cord injury (SCI)-induced bladder dysfunction is detrusor overactivity (DO). Although a myogenic origin of DO after SCI has been suggested, a mechanism for development of SCI-induced DO has not been determined. In this study we hypothesized that SCI-induced DO is related to loss of function in the regulatory mechanism provided by PDGFRα+ cells. Our results showed that transcriptional expression of Pdgfra and Kcnn3 was decreased after SCI. Proteins encoded by these genes also decreased after SCI, and a reduction in PDGFRα+ cell density was also documented. Loss of PDGFRα+ cells was due to apoptosis. TCs in ex vivo bladders during filling increased dramatically after SCI, and this was related to the loss of regulation provided by SK channels, as we observed decreased sensitivity to apamin. These findings show that damage to the mechanism restraining muscle contraction during bladder filling that is provided by PDGFRα+ cells is causative in the development of DO after SCI.

scholarly journals Molecular identification and functional characterization of an adenylyl cyclase from the honeybee

2006 ◽  
Vol 96 (6) ◽  
pp. 1580-1590 ◽  
Author(s):  
Sebastian Wachten ◽  
Jana Schlenstedt ◽  
Renate Gauss ◽  
Arnd Baumann
Keyword(s):  
Adenylyl Cyclase ◽  
Molecular Identification ◽  
Functional Characterization

scholarly journals TSG (2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside) from the Chinese HerbPolygonum multiflorumIncreases Life Span and Stress Resistance ofCaenorhabditis elegans

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Christian Büchter ◽  
Liang Zhao ◽  
Susannah Havermann ◽  
Sebastian Honnen ◽  
Gerhard Fritz ◽  
...  
Keyword(s):  
Life Span ◽  
Stress Resistance ◽  
Adult Life ◽  
Model Organism ◽  
Antioxidative Capacity ◽  
Loss Of Function ◽  
Polygonum Multiflorum ◽  
Adult Life Span ◽  
C Elegans ◽  
Related Transcription Factor

2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) was isolated fromPolygonum multiflorum, a plant which is traditionally used as an anti-ageing drug. We have analysed ageing-related effects of TSG in the model organismC. elegansin comparison to resveratrol. TSG exerted a high antioxidative capacity both in a cell-free assay and in the nematode. The antioxidative capacity was even higher compared to resveratrol. Presumably due to its antioxidative effects, treatment with TSG decreased the juglone-mediated induction of the antioxidative enzyme SOD-3; the induction of the GST-4 by juglone was diminished slightly. TSG increased the resistance ofC. elegansagainst lethal thermal stress more prominently than resveratrol (50 μM TSG increased mean survival by 22.2%). The level of the ageing pigment lipofuscin was decreased after incubation with the compound. TSG prolongs the mean, median, and maximum adult life span ofC. elegansby 23.5%, 29.4%, and 7.2%, respectively, comparable to the effects of resveratrol. TSG-mediated extension of life span was not abolished in a DAF-16 loss-of-function mutant strain showing that this ageing-related transcription factor is not involved in the effects of TSG. Our data show that TSG possesses a potent antioxidative capacity, enhances the stress resistance, and increases the life span of the nematodeC. elegans.

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