scholarly journals APC/CFZR-1 regulates centrosomal ZYG-1 to limit centrosome number

2021 ◽  
Author(s):  
Jeffrey C. Medley ◽  
Joseph R. DiPanni ◽  
Luke Schira ◽  
Blake M. Shaffou ◽  
Brandon M. Sebou ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Threshold Level ◽  
Anaphase Promoting Complex ◽  
Tight Control ◽  
C Elegans ◽  
Protein Levels ◽  
Bipolar Spindles ◽  
Embryonic Viability ◽  
Centrosome Protein ◽  
Potential Substrate

Aberrant centrosome numbers are associated with human cancers. The levels of centrosome regulators positively correlate with centrosome number. Thus, tight control of centrosome protein levels is critical. In Caenorhabditis elegans, the anaphase-promoting complex/cyclosome and co-activator FZR-1 (APC/CFZR-1) ubiquitin ligase negatively regulates centrosome assembly through SAS-5 degradation. In this study, we report the C. elegans ZYG-1 (Plk4 in human) as a potential substrate of APC/CFZR-1. Inhibiting APC/CFZR-1 or mutating a ZYG-1 destruction (D)-box leads to elevated ZYG-1 levels at centrosomes, restoring bipolar spindles and embryonic viability to zyg-1 mutants, suggesting that APC/CFZR-1 influences centrosomal ZYG-1 via D-box motif. We also show the Slimb/βTrCP-binding (SB) motif is critical for ZYG-1 degradation, substantiating a conserved mechanism by which ZYG-1/Plk4 stability is regulated by SCFSlimb/βTrCP-dependent proteolysis via the conserved SB motif in C. elegans. Furthermore, we show that co-mutating ZYG-1 SB and D-box motifs stabilizes ZYG-1 in an additive manner, suggesting that APC/CFZR-1 and SCFSlimb/βTrCP ubiquitin ligases function cooperatively for timely ZYG-1 destruction in C. elegans embryos where ZYG-1 activity remains at threshold level to ensure normal centrosome number.

scholarly journals APC/CFZR-1 Controls ZYG-1 Levels to Regulate Centrosome Assembly

2020 ◽  
Author(s):  
Jeffrey C. Medley ◽  
Joseph R. DiPanni ◽  
Luke Schira ◽  
Blake M. Shaffou ◽  
Brandon M. Sebou ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Ubiquitin Ligase ◽  
Threshold Level ◽  
Anaphase Promoting Complex ◽  
Tight Control ◽  
C Elegans ◽  
Protein Levels ◽  
Bipolar Spindles ◽  
Embryonic Viability ◽  
Centrosome Protein

AbstractAberrant centrosome numbers are associated with human cancers. The levels of centrosome regulators positively correlate with centrosome number. Thus, tight control of centrosome protein levels is critical. In Caenorhabditis elegans, the anaphase-promoting complex/cyclosome and co-activator FZR-1 (APC/CFZR-1) ubiquitin ligase negatively regulates centrosome assembly through SAS-5 degradation. In this study, we identify the C. elegans ZYG-1 (Plk4 in human) as a new substrate of APC/CFZR-1. Inhibiting APC/CFZR-1 or mutating a ZYG-1 destruction (D)-box leads to elevated ZYG-1 levels at centrosomes, restoring bipolar spindles and embryonic viability to zyg-1 mutants, suggesting that APC/CFZR-1 targets ZYG-1 for proteasomal degradation via D-box motif. We also show the Slimb/βTrCP-binding (SB) motif is critical for ZYG-1 degradation, substantiating a conserved mechanism by which ZYG-1/Plk4 stability is regulated by SCFSlimb/βTrCP-dependent proteolysis via the conserved SB motif in C. elegans. Furthermore, inhibiting both APC/CFZR-1 and SCFSlimb/βTrCP, by co-mutating ZYG-1 SB and D-box motifs, stabilizes ZYG-1 in an additive manner, conveying that APC/CFZR-1 and SCFSlimb/βTrCP ubiquitin ligases function cooperatively for timely ZYG-1 destruction in C. elegans embryos where ZYG-1 activity remains at threshold level to ensure normal centrosome number.

scholarly journals The Anaphase-Promoting Complex (APC) ubiquitin ligase affects chemosensory behavior inC. elegans

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2013 ◽  
Author(s):  
Julia Wang ◽  
Alexandra K. Jennings ◽  
Jennifer R. Kowalski
Keyword(s):  
Sensory Neurons ◽  
Ubiquitin Ligase ◽  
Isoamyl Alcohol ◽  
Sensory Function ◽  
Anaphase Promoting Complex ◽  
Loss Of Function ◽  
Wild Type ◽  
C Elegans ◽  
The Difference ◽  
Hypomorphic Alleles

The regulation of fundamental aspects of neurobiological function has been linked to the ubiquitin signaling system (USS), which regulates the degradation and activity of proteins and is catalyzed by E1, E2, and E3 enzymes. The Anaphase-Promoting Complex (APC) is a multi-subunit E3 ubiquitin ligase that controls diverse developmental and signaling processes in post-mitotic neurons; however, potential roles for the APC in sensory function have yet to be explored. In this study, we examined the effect of the APC ubiquitin ligase on chemosensation inCaenorhabditis elegansby testing chemotaxis to the volatile odorants, diacetyl, pyrazine, and isoamyl alcohol, to which wild-type worms are attracted. Animals with loss of function mutations in either of two alleles (g48andye143) of the gene encoding the APC subunit EMB-27 APC6 showed increased chemotaxis towards diacetyl and pyrazine, odorants sensed by AWA neurons, but exhibited normal chemotaxis to isoamyl alcohol, which is sensed by AWC neurons. The statistically significant increase in chemotaxis in theemb-27 APC6mutants suggests that the APC inhibits AWA-mediated chemosensation inC. elegans. Increased chemotaxis to pyrazine was also seen with mutants lacking another essential APC subunit, MAT-2 APC1; however,mat-2 APC1mutants exhibited wild type responses to diacetyl. The difference in responsiveness of these two APC subunit mutants may be due to differential strength of these hypomorphic alleles or may indicate the presence of functional sub-complexes of the APC at work in this process. These findings are the first evidence for APC-mediated regulation of chemosensation and lay the groundwork for further studies aimed at identifying the expression levels, function, and targets of the APC in specific sensory neurons. Because of the similarity between human andC. elegansnervous systems, the role of the APC in sensory neurons may also advance our understanding of human sensory function and disease.

scholarly journals The Anaphase-Promoting Complex (APC) ubiquitin ligase regulates GABA transmission at the C. elegans neuromuscular junction

2014 ◽  
Vol 58 ◽  
pp. 62-75 ◽  
Author(s):  
Jennifer R. Kowalski ◽  
Hitesh Dube ◽  
Denis Touroutine ◽  
Kristen M. Rush ◽  
Patricia R. Goodwin ◽  
...  
Keyword(s):  
Neuromuscular Junction ◽  
Ubiquitin Ligase ◽  
Anaphase Promoting Complex ◽  
C Elegans ◽  
Gaba Transmission

scholarly journals The ubiquitin ligase CRL2ZYG11 targets cyclin B1 for degradation in a conserved pathway that facilitates mitotic slippage

2016 ◽  
Vol 215 (2) ◽  
pp. 151-166 ◽  
Author(s):  
Riju S. Balachandran ◽  
Cassandra S. Heighington ◽  
Natalia G. Starostina ◽  
James W. Anderson ◽  
David L. Owen ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Spindle Assembly Checkpoint ◽  
Cyclin B1 ◽  
Human Cells ◽  
Anaphase Promoting Complex ◽  
Mitotic Progression ◽  
Animal Cells ◽  
C Elegans ◽  
Chemotherapy Drugs ◽  
Mitotic Slippage

The anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase is known to target the degradation of cyclin B1, which is crucial for mitotic progression in animal cells. In this study, we show that the ubiquitin ligase CRL2ZYG-11 redundantly targets the degradation of cyclin B1 in Caenorhabditis elegans and human cells. In C. elegans, both CRL2ZYG-11 and APC/C are required for proper progression through meiotic divisions. In human cells, inactivation of CRL2ZYG11A/B has minimal effects on mitotic progression when APC/C is active. However, when APC/C is inactivated or cyclin B1 is overexpressed, CRL2ZYG11A/B-mediated degradation of cyclin B1 is required for normal progression through metaphase. Mitotic cells arrested by the spindle assembly checkpoint, which inactivates APC/C, often exit mitosis in a process termed “mitotic slippage,” which generates tetraploid cells and limits the effectiveness of antimitotic chemotherapy drugs. We show that ZYG11A/B subunit knockdown, or broad cullin–RING ubiquitin ligase inactivation with the small molecule MLN4924, inhibits mitotic slippage in human cells, suggesting the potential for antimitotic combination therapy.

scholarly journals Global phosphoproteomics reveals DYRK1A regulates CDK1 activity in glioblastoma cells

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ariadna Recasens ◽  
Sean J. Humphrey ◽  
Michael Ellis ◽  
Monira Hoque ◽  
Ramzi H. Abbassi ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Cyclin B ◽  
Anaphase Promoting Complex ◽  
Mechanistic Studies ◽  
Glioblastoma Cells ◽  
Cycle Arrest ◽  
Dual Specificity ◽  
Rb Pathway ◽  
High Doses

AbstractBoth tumour suppressive and oncogenic functions have been reported for dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). Herein, we performed a detailed investigation to delineate the role of DYRK1A in glioblastoma. Our phosphoproteomic and mechanistic studies show that DYRK1A induces degradation of cyclin B by phosphorylating CDC23, which is necessary for the function of the anaphase-promoting complex, a ubiquitin ligase that degrades mitotic proteins. DYRK1A inhibition leads to the accumulation of cyclin B and activation of CDK1. Importantly, we established that the phenotypic response of glioblastoma cells to DYRK1A inhibition depends on both retinoblastoma (RB) expression and the degree of residual DYRK1A activity. Moderate DYRK1A inhibition leads to moderate cyclin B accumulation, CDK1 activation and increased proliferation in RB-deficient cells. In RB-proficient cells, cyclin B/CDK1 activation in response to DYRK1A inhibition is neutralized by the RB pathway, resulting in an unchanged proliferation rate. In contrast, complete DYRK1A inhibition with high doses of inhibitors results in massive cyclin B accumulation, saturation of CDK1 activity and cell cycle arrest, regardless of RB status. These findings provide new insights into the complexity of context-dependent DYRK1A signalling in cancer cells.

scholarly journals Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo

2021 ◽  
Author(s):  
Dorothy Benton ◽  
Eva C Jaeger ◽  
Arielle Kilner ◽  
Ashley Kimble ◽  
Josh Lowry ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Oocyte Maturation ◽  
Protective Role ◽  
C Elegans ◽  
Direct Target ◽  
The One ◽  
Actomyosin Cytoskeleton ◽  
Embryonic Viability ◽  
Anterior Posterior

Abstract Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior-posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. While the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome-cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. While depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.

scholarly journals Eukaryotic initiation factor EIF-3.G augments mRNA translation efficiency to regulate neuronal activity

2021 ◽  
Author(s):  
Stephen M Blazie ◽  
Seika Takayanagi-Kiya ◽  
Katherine A McCulloch ◽  
Yishi Jin
Keyword(s):  
Rna Binding ◽  
Mrna Translation ◽  
Initiation Factor ◽  
Translation Efficiency ◽  
Dependent Manner ◽  
Control Activity ◽  
C Elegans ◽  
Protein Levels ◽  
Neuronal Protein

AbstractThe translation initiation complex eIF3 imparts specialized functions to regulate protein expression. However, understanding of eIF3 activities in neurons remains limited despite widespread dysregulation of eIF3 subunits in neurological disorders. Here, we report a selective role of theC. elegansRNA-binding subunit EIF-3.G in shaping the neuronal protein landscape. We identify a missense mutation in the conserved Zinc-Finger (ZF) of EIF-3.G that acts in a gain-of-function manner to dampen neuronal hyperexcitation. Using neuron type-specific seCLIP, we systematically mapped EIF-3.G-mRNA interactions and identified EIF-3.G occupancy on GC-rich 5′UTRs of a select set of mRNAs enriched in activity-dependent functions. We demonstrate that the ZF mutation in EIF-3.G alters translation in a 5′UTR dependent manner. Our study reveals anin vivomechanism for eIF3 in governing neuronal protein levels to control activity states and offers insights into how eIF3 dysregulation contributes to neuronal disorders.

scholarly journals An intracellular pathogen response pathway promotes proteostasis in C. elegans

2017 ◽  
Author(s):  
Kirthi C. Reddy ◽  
Tal Dror ◽  
Jessica N. Sowa ◽  
Johan Panek ◽  
Kevin Chen ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Intracellular Pathogen ◽  
Forward Genetic Screen ◽  
C Elegans ◽  
Transcriptional Signature ◽  
Proteotoxic Stress ◽  
Ubiquitin Ligase Complex ◽  
Pathogen Response ◽  
Mutant Phenotypes ◽  
Increased Activity

SummaryMaintenance of proteostasis is critical for organismal health. Here we describe a novel pathway that promotes proteostasis, identified through the analysis of C. elegans genes upregulated by intracellular infection. We named this distinct transcriptional signature the Intracellular Pathogen Response (IPR), and it includes upregulation of several predicted ubiquitin ligase complex components such as the cullin cul-6. Through a forward genetic screen we found pals-22, a gene of previously unknown function, to be a repressor of the cul-6/Cullin gene and other IPR gene expression. Interestingly, pals-22 mutants have increased thermotolerance and reduced levels of stress-induced polyglutamine aggregates, likely due to upregulated IPR expression. We found the enhanced stress resistance of pals-22 mutants to be dependent on cul-6, suggesting that pals-22 mutants have increased activity of a CUL-6/Cullin-containing ubiquitin ligase complex. pals-22 mutant phenotypes are distinct from the well-studied heat shock and insulin signaling pathways, indicating that the IPR is a novel pathway that protects animals from proteotoxic stress.

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