scholarly journals The WD40-repeat protein CreC interacts with and stabilizes the deubiquitinating enzyme CreB in vivo in Aspergillus nidulans

2002 ◽  
Vol 43 (5) ◽  
pp. 1173-1182 ◽  
Author(s):  
Robin A. Lockington ◽  
Joan M. Kelly
2019 ◽  
Author(s):  
Molly Hodul ◽  
Rakesh Ganji ◽  
Caroline L Dahlberg ◽  
Malavika Raman ◽  
Peter Juo

ABSTRACTUbiquitination is a reversible post-translational modification that has emerged as a critical regulator of synapse development and function. However, mechanisms that regulate the deubiquitinating enzymes (DUBs) that are responsible for the removal of ubiquitin from target proteins are poorly understood. We previously showed that the DUB USP-46 removes ubiquitin from the glutamate receptor GLR-1 and regulates it trafficking and degradation in C. elegans. We found that WD40-repeat proteins WDR-20 and WDR-48 bind and stimulate the catalytic activity of USP-46. Here, we identify another mechanism by which WDR-48 regulates USP-46. We found that increased expression of WDR-48, but not WDR-20, promotes USP-46 abundance in mammalian cells in culture and in C. elegans neurons in vivo. Inhibition of the proteasome promotes the abundance of USP-46, and this effect is non-additive with increased expression of WDR-48. We found that USP-46 is ubiquitinated, and expression of WDR-48 reduces the levels of ubiquitin-USP-46 conjugates and increases the half-life of USP-46. A point mutant version of WDR-48 that disrupts binding to USP-46 is unable to promote USP-46 abundance in vivo. Together, these data support a model in which WDR-48 binds and stabilizes USP-46 protein levels by preventing the ubiquitination and degradation of USP-46 in the proteasome. Given that a large number of USPs interact with WDR proteins, we propose that stabilization of DUBs by their interacting WDR proteins may be a conserved and widely used mechanism to control DUB availability and function.


2021 ◽  
pp. JN-RM-1074-20
Author(s):  
Molly Hodul ◽  
Bethany J. Rennich ◽  
Eric S. Luth ◽  
Caroline L. Dahlberg ◽  
Peter Juo

2021 ◽  
Vol 7 (7) ◽  
pp. 514
Author(s):  
Mariangela Dionysopoulou ◽  
George Diallinas

Recent biochemical and biophysical evidence have established that membrane lipids, namely phospholipids, sphingolipids and sterols, are critical for the function of eukaryotic plasma membrane transporters. Here, we study the effect of selected membrane lipid biosynthesis mutations and of the ergosterol-related antifungal itraconazole on the subcellular localization, stability and transport kinetics of two well-studied purine transporters, UapA and AzgA, in Aspergillus nidulans. We show that genetic reduction in biosynthesis of ergosterol, sphingolipids or phosphoinositides arrest A. nidulans growth after germling formation, but solely blocks in early steps of ergosterol (Erg11) or sphingolipid (BasA) synthesis have a negative effect on plasma membrane (PM) localization and stability of transporters before growth arrest. Surprisingly, the fraction of UapA or AzgA that reaches the PM in lipid biosynthesis mutants is shown to conserve normal apparent transport kinetics. We further show that turnover of UapA, which is the transporter mostly sensitive to membrane lipid content modification, occurs during its trafficking and by enhanced endocytosis, and is partly dependent on autophagy and Hect-type HulARsp5 ubiquitination. Our results point out that the role of specific membrane lipids on transporter biogenesis and function in vivo is complex, combinatorial and transporter-dependent.


2003 ◽  
Vol 38 (2) ◽  
pp. 175-186 ◽  
Author(s):  
Agnieszka Dzikowska ◽  
Magdalena Kacprzak ◽  
Rafał Tomecki ◽  
Michał Koper ◽  
Claudio Scazzocchio ◽  
...  

2005 ◽  
Vol 71 (5) ◽  
pp. 2737-2747 ◽  
Author(s):  
Andrew H. Sims ◽  
Manda E. Gent ◽  
Karin Lanthaler ◽  
Nigel S. Dunn-Coleman ◽  
Stephen G. Oliver ◽  
...  

ABSTRACT Filamentous fungi have a high capacity for producing large amounts of secreted proteins, a property that has been exploited for commercial production of recombinant proteins. However, the secretory pathway, which is key to the production of extracellular proteins, is rather poorly characterized in filamentous fungi compared to yeast. We report the effects of recombinant protein secretion on gene expression levels in Aspergillus nidulans by directly comparing a bovine chymosin-producing strain with its parental wild-type strain in continuous culture by using expressed sequence tag microarrays. This approach demonstrated more subtle and specific changes in gene expression than those observed when mimicking the effects of protein overproduction by using a secretion blocker. The impact of overexpressing a secreted recombinant protein more closely resembles the unfolded-protein response in vivo.


2008 ◽  
Vol 17 (4) ◽  
pp. 163-170 ◽  
Author(s):  
Myung Whan Suh ◽  
Dong Hoon Shin ◽  
Ho Sun Lee ◽  
Ji Yeong Park ◽  
Chong Sun Kim ◽  
...  

Unlike mammals, avian cochlear hair cells can regenerate after acoustic overstimulation. The WDR1 gene is one of the genes suspected to play an important role in this difference. In an earlier study, we found that the WDR1 gene is over-expressed in the chick cochlea after acoustic overstimulation. The aim of this study was to compare the expression of WDR1 before and after acoustic overstimulation in the chick vestibule. Seven-day-old chicks were divided into three groups: normal group, damage group, and regeneration group. The damage and regeneration group was exposed to 120 dB SPL white noise for 5–6 hours. The damage group was euthanized shortly after the impulse, but the regeneration group was allowed to recover for 2 days. The utricle, saccule, and the three ampullae of each semicircular canal were dissected and immunohistochemically stained with anti-WD40 repeat protein 1 antibody. For quantitative analysis, immunoreactive densities were measured and quantitative real-time RT PCR was performed. WD40 repeat protein 1 expression was elevated in all the semicircular canals and utricle, two days after an acoustic overstimulation (P = 0.001). WDR1 mRNA expression was 1.34 times higher in the regeneration group compared to the normal group, but it was not statistically significant. Exceptionally, WD40 repeat protein 1 expression did not increase in the saccule of the regeneration group. Elevated WDR1 expression in the avian vestibule may have a role in the hair cell regenerating ability as in the avian cochlea. A similar mechanism of hair cell regeneration may exist in the avian cochlea and vestibule.


2020 ◽  
Vol 21 (16) ◽  
pp. 5638
Author(s):  
Jinhong Cho ◽  
Jinyoung Park ◽  
Eunice EunKyeong Kim ◽  
Eun Joo Song

Deubiquitinating enzymes regulate various cellular processes, particularly protein degradation, localization, and protein–protein interactions. The dysregulation of deubiquitinating enzyme (DUB) activity has been linked to several diseases; however, the function of many DUBs has not been identified. Therefore, the development of methods to assess DUB activity is important to identify novel DUBs, characterize DUB selectivity, and profile dynamic DUB substrates. Here, we review various methods of evaluating DUB activity using cell lysates or purified DUBs, as well as the types of probes used in these methods. In addition, we introduce some techniques that can deliver DUB probes into the cells and cell-permeable activity-based probes to directly visualize and quantify DUB activity in live cells. This review could contribute to the development of DUB inhibitors by providing important information on the characteristics and applications of various probes used to evaluate and detect DUB activity in vitro and in vivo.


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