scholarly journals The novel ciliogenesis regulator DYRK2 governs Hedgehog signaling during mouse embryogenesis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Saishu Yoshida ◽  
Katsuhiko Aoki ◽  
Ken Fujiwara ◽  
Takashi Nakakura ◽  
Akira Kawamura ◽  
...  

Mammalian Hedgehog (Hh) signaling plays key roles in embryogenesis and uniquely requires primary cilia. Functional analyses of several ciliogenesis-related genes led to the discovery of the developmental diseases known as ciliopathies. Hence, identification of mammalian factors that regulate ciliogenesis can provide insight into the molecular mechanisms of embryogenesis and ciliopathy. Here, we demonstrate that DYRK2 acts as a novel mammalian ciliogenesis-related protein kinase. Loss of Dyrk2 in mice causes suppression of Hh signaling and results in skeletal abnormalities during in vivo embryogenesis. Deletion of Dyrk2 induces abnormal ciliary morphology and trafficking of Hh pathway components. Mechanistically, transcriptome analyses demonstrate down-regulation of Aurka and other disassembly genes following Dyrk2 deletion. Taken together, the present study demonstrates for the first time that DYRK2 controls ciliogenesis and is necessary for Hh signaling during mammalian development.

2015 ◽  
Vol 112 (16) ◽  
pp. 5069-5074 ◽  
Author(s):  
LaGina Nosavanh ◽  
Da-Hai Yu ◽  
Eric J. Jaehnig ◽  
Qiang Tong ◽  
Lanlan Shen ◽  
...  

Although recent studies have shown that brown adipose tissue (BAT) arises from progenitor cells that also give rise to skeletal muscle, the developmental signals that control the formation of BAT remain largely unknown. Here, we show that brown preadipocytes possess primary cilia and can respond to Hedgehog (Hh) signaling. Furthermore, cell-autonomous activation of Hh signaling blocks early brown-preadipocyte differentiation, inhibits BAT formation in vivo, and results in replacement of neck BAT with poorly differentiated skeletal muscle. Finally, we show that Hh signaling inhibits BAT formation partially through up-regulation of chicken ovalbumin upstream promoter transcription factor II (COUP-TFII). Taken together, our studies uncover a previously unidentified role for Hh as an inhibitor of BAT development.


1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.


Development ◽  
2001 ◽  
Vol 128 (24) ◽  
pp. 4993-5004
Author(s):  
Nathalie Spassky ◽  
Katharina Heydon ◽  
Arnaud Mangatal ◽  
Alexandar Jankovski ◽  
Christelle Olivier ◽  
...  

Most studies on the origin of oligodendrocyte lineage have been performed in the spinal cord. By contrast, molecular mechanisms that regulate the appearance of the oligodendroglial lineage in the brain have not yet attracted much attention. We provide evidence for three distinct sources of oligodendrocytes in the mouse telencephalon. In addition to two subpallial ventricular foci, the anterior entopeduncular area and the medial ganglionic eminence, the rostral telencephalon also gives rise to oligodendrocytes. We show that oligodendrocytes in the olfactory bulb are generated within the rostral pallium from ventricular progenitors characterized by the expression of Plp. We provide evidence that these Plp oligodendrocyte progenitors do not depend on signal transduction mediated by platelet-derived growth factor receptors (PDGFRs), and therefore propose that they belong to a different lineage than the PDGFRα-expressing progenitors. Moreover, induction of oligodendrocytes in the telencephalon is dependent on sonic hedgehog signaling, as in the spinal cord. In all these telencephalic ventricular territories, oligodendrocyte progenitors were detected at about the same developmental stage as in the spinal cord. However, both in vivo and in vitro, the differentiation into O4-positive pre-oligodendrocytes was postponed by 4-5 days in the telencephalon in comparison with the spinal cord. This delay between determination and differentiation appears to be intrinsic to telencephalic oligodendrocytes, as it was not shortened by diffusible or cell-cell contact factors present in the spinal cord.


2021 ◽  
Author(s):  
Megan Lo ◽  
Amnon Sharir ◽  
Michael D Paul ◽  
Hayarpi Torosyan ◽  
Christopher Agnew ◽  
...  

The Hedgehog (HH) pathway is critical for development and adult tissue homeostasis. Aberrant HH signaling can cause congenital malformations, such as digit anomalies and holoprosencephaly, and other diseases, including cancer. Signal transduction is initiated by HH ligand binding to the Patched 1 (PTCH1) receptor on primary cilia, thereby releasing inhibition of Smoothened (SMO), a HH pathway activator. Although cholesterol and several oxysterol lipids, which are enriched in the ciliary membrane, play a crucial role in HH activation, the molecular mechanisms governing the regulation of these lipid molecules remain unresolved. Here, we identify Canopy 4 (CNPY4), a Saposin-like protein, as a regulator of the HH pathway that controls membrane sterol lipid levels. Cnpy4—/— embryos exhibit multiple defects consistent with HH signaling perturbations, most notably changes in digit number. Knockdown of Cnpy4 hyperactivates the HH pathway at the level of SMO in vitro, and elevates membrane levels of accessible sterol lipids such as cholesterol, an endogenous ligand involved in SMO activation. Thus, our data demonstrate that CNPY4 is a negative regulator that fine-tunes the initial steps of HH signal transduction, revealing a previously undescribed facet of HH pathway regulation that operates through control of membrane composition.


2002 ◽  
Vol 115 (5) ◽  
pp. 923-929 ◽  
Author(s):  
Yosef Gruenbaum ◽  
Kenneth K. Lee ◽  
Jun Liu ◽  
Merav Cohen ◽  
Katherine L. Wilson

Emerin belongs to the LEM-domain family of nuclear membrane proteins, which are conserved in metazoans from C. elegans to humans. Loss of emerin in humans causes the X-linked form of Emery-Dreifuss muscular dystrophy(EDMD), but the disease mechanism is not understood. We have begun to address the function of emerin in C. elegans, a genetically tractable nematode. The emerin gene (emr-1) is conserved in C. elegans. We detect Ce-emerin protein in the nuclear envelopes of all cell types except sperm, and find that Ce-emerin co-immunoprecipitates with Ce-lamin from embryo lysates. We show for the first time in any organism that nuclear lamins are essential for the nuclear envelope localization of emerin during early development. We further show that four other types of nuclear envelope proteins, including fellow LEM-domain protein Ce-MAN1, as well as Ce-lamin, UNC-84 and nucleoporins do not depend on Ce-emerin for their localization. This result suggests that emerin is not essential to organize or localize the only lamin (B-type) expressed in C. elegans. We also analyzed the RNAi phenotype resulting from the loss of emerin function in C. elegans under laboratory growth conditions, and found no detectable phenotype throughout development. We propose that C. elegans is an appropriate system in which to study the molecular mechanisms of emerin function in vivo.


2021 ◽  
Vol 16 (9) ◽  
pp. 1934578X2110350
Author(s):  
Lijun Cheng ◽  
Yang Deng

Gastrodin (GAS) and its aglycone, p-hydroxybenzyl alcohol (HBA), are both bioactive compounds extracted from Gastrodia elata Blume (GEB). In the current Chinese pharmacopoeia, they are regarded as quality control markers for GEB. In this study, we developed a high-performance liquid chromatography method coupled with a diode array detector to quantify GAS and HBA concentrations in plasma following oral ingestion by rats. For the first time, GAS was detected in vivo after HBA administration. GAS and HBA both had similar pharmacological effects, but the influence of the glucose moiety resulted in different pharmacokinetic characteristics. In this study, the effects of GAS and HBA at different administration durations were investigated in zebrafish larvae. These compounds were found to induce a sedative effect but had different onset times. In conclusion, a biotransformation of HBA to GAS could be observed in the rats. This may be a new insight into the pharmacokinetic characteristics of these bioactive compounds and also relates to the different ways in which they take effect.


Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Qian Peng ◽  
Xuekun Tang ◽  
Kun Liu ◽  
Xianping Luo ◽  
Dongsheng He ◽  
...  

In the study, magnesium oxide (MgO) was used to catalyze peroxymonosulfate (PMS) for the degradation of organic pollutants for the first time. According to the single-factor experiment results, it was determined that MgO could efficiently catalyze PMS to degrade organic matters in a wide range of pH values. Based on radical quenching experiments and electron spinning resonance spectra, singlet oxygen was identified to be the crucial reactive species. Importantly, the oxygen vacancy on the surface of MgO was determined as the key active site, which accelerated the decomposition of PMS to produce singlet oxygen. This study provides an interesting insight into the novel and ignored catalyst of MgO for the highly efficient activation of PMS, which will greatly benefit the Fenton-like catalytic degradation of organic wastewater.


2018 ◽  
Vol 97 (13) ◽  
pp. 1485-1493 ◽  
Author(s):  
N.L. Hammond ◽  
K.J. Brookes ◽  
M.J. Dixon

Cleft palate is a common birth defect that frequently occurs in human congenital malformations caused by mutations in components of the Sonic Hedgehog (S HH) signaling cascade. Shh is expressed in dynamic, spatiotemporal domains within epithelial rugae and plays a key role in driving epithelial-mesenchymal interactions that are central to development of the secondary palate. However, the gene regulatory networks downstream of Hedgehog (Hh) signaling are incompletely characterized. Here, we show that ectopic Hh signaling in the palatal mesenchyme disrupts oral-nasal patterning of the neural crest cell–derived ectomesenchyme of the palatal shelves, leading to defective palatine bone formation and fully penetrant cleft palate. We show that a series of Fox transcription factors, including the novel direct target Foxl1, function downstream of Hh signaling in the secondary palate. Furthermore, we demonstrate that Wnt/bone morphogenetic protein (BMP) antagonists, in particular Sostdc1, are positively regulated by Hh signaling, concomitant with downregulation of key regulators of osteogenesis and BMP signaling effectors. Our data demonstrate that ectopic Hh-Smo signaling downregulates Wnt/BMP pathways, at least in part by upregulating Sostdc1, resulting in cleft palate and defective osteogenesis.


Blood ◽  
2010 ◽  
Vol 116 (10) ◽  
pp. 1767-1775 ◽  
Author(s):  
Markus Bender ◽  
Anita Eckly ◽  
John H. Hartwig ◽  
Margitta Elvers ◽  
Irina Pleines ◽  
...  

Abstract The cellular and molecular mechanisms orchestrating the complex process by which bone marrow megakaryocytes form and release platelets remain poorly understood. Mature megakaryocytes generate long cytoplasmic extensions, proplatelets, which have the capacity to generate platelets. Although microtubules are the main structural component of proplatelets and microtubule sliding is known to drive proplatelet elongation, the role of actin dynamics in the process of platelet formation has remained elusive. Here, we tailored a mouse model lacking all ADF/n-cofilin–mediated actin dynamics in megakaryocytes to specifically elucidate the role of actin filament turnover in platelet formation. We demonstrate, for the first time, that in vivo actin filament turnover plays a critical role in the late stages of platelet formation from megakaryocytes and the proper sizing of platelets in the periphery. Our results provide the genetic proof that platelet production from megakaryocytes strictly requires dynamic changes in the actin cytoskeleton.


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