Identification and characterization of<i><scp>P</scp>l</i>Alix, the<scp>A</scp>lix homologue from the<scp>M</scp>editerranean sea urchin<i><scp>P</scp>aracentrotus lividus</i>

Romancino, Daniele P.; Anello, Letizia; Morici, Giovanni; d’Azzo, Alessandra; Bongiovanni, Antonella; Bernardo, Maria Di

doi:10.1111/dgd.12023

Cited by 5 publications

(5 citation statements)

References 41 publications

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“…Almost all genes involved in development and differentiation processes were affected by both HEPEs. Alix is a multifunctional protein involved in different cellular processes, including endocytic membrane trafficking, filamentous-actin remodeling, and cytokinesis ( Romancino et al , 2013 ). In sea urchins, this transcript encodes for a maternal protein involved in determination/differentiation events that is expressed from fertilization to the 2-cell stage.…”

Section: Discussionmentioning

confidence: 99%

First Morphological and Molecular Evidence of the Negative Impact of Diatom-Derived Hydroxyacids on the Sea UrchinParacentrotus lividus

Varrella¹,

Romano

Ruocco³

et al. 2016

Toxicol. Sci.

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Oxylipins (including polyunsaturated aldehydes [PUAs], hydoxyacids, and epoxyalcohols) are the end-products of a lipoxygenase/hydroperoxide lyase metabolic pathway in diatoms. To date, very little information is available on oxylipins other than PUAs, even though they represent the most common oxylipins produced by diatoms. Here, we report, for the first time, on the effects of 2 hydroxyacids, 5- and 15-HEPE, which have never been tested before, using the sea urchin Paracentrotus lividus as a model organism. We show that HEPEs do induce developmental malformations but at concentrations higher when compared with PUAs. Interestingly, HEPEs also induced a marked developmental delay in sea urchin embryos, which has not hitherto been reported for PUAs. Recovery experiments revealed that embryos do not recover following treatment with HEPEs. Finally, we report the expression levels of 35 genes (involved in stress, development, differentiation, skeletogenesis, and detoxification processes) to identify the molecular targets affected by HEPEs. We show that the 2 HEPEs have very few common molecular targets, specifically affecting different classes of genes and at different times of development. In particular, 15-HEPE switched on fewer genes than 5-HEPE, upregulating mainly stress-related genes at a later pluteus stage of development. 5-HEPE was stronger than 15-HEPE, targeting 24 genes, mainly at the earliest stages of embryo development (at the blastula and swimming blastula stages). These findings highlight the differences between HEPEs and PUAs and also have important ecological implications because many diatom species do not produce PUAs, but rather these other chemicals are derived from the oxidation of fatty acids.

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Section: Discussionmentioning

confidence: 99%

First Morphological and Molecular Evidence of the Negative Impact of Diatom-Derived Hydroxyacids on the Sea UrchinParacentrotus lividus

Varrella¹,

Romano

Ruocco³

et al. 2016

Toxicol. Sci.

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“…The sox9 gene was upregulated by heptadienal at the prism stage, suggesting an effect on left-right asymmetry processes [47]. Alix , a multifunctional protein involved in different cellular processes, including endocytic membrane trafficking, filamentous-actin remodelling and cytokinesis [15], was upregulated only by heptadienal at the pluteus stage. In sea urchins, this transcript encodes for a maternal protein involved in determination/differentiation events that is expressed from fertilization to the two-cell embryo stage.…”

Section: Discussionmentioning

confidence: 99%

“…The expression level of seventeen genes, previously analysed by real-time qPCR in Marrone et al [13], were analysed together with fourteen new genes (see Table 1): Pl-p19 ( p19 ), Pl-p16 ( p16 ; [14]), metallothionein 4 ( MT4 ; [21]), metallothionein 5 ( MT5 ; [21]), metallothionein 6 ( MT6 ; [21]), metallothionein 7 ( MT7 ; [21], metallothionein 8 ( MT8 ; [21]), blimp ( Blimp ; [16]), ALG-2 interacting protein X/1( Alix ; [15]), multi-drug resistance protein 1 ( MDR 1 ), Wnt5 ( Wnt5 ), Wnt6 ( Wnt6 ) and Wnt8 ( Wnt8 ). We also analysed the catalase gene ( CAT ); since the CAT sequence of P. lividus is not available, a 156-bp fragment was amplified using specific primers for this gene from Strongylocentrotus purpuratus .…”

Section: Methodsmentioning

confidence: 99%

Molecular Response to Toxic Diatom-Derived Aldehydes in the Sea Urchin Paracentrotus lividus

et al. 2014

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Diatoms are dominant photosynthetic organisms in the world’s oceans and represent a major food source for zooplankton and benthic filter-feeders. However, their beneficial role in sustaining marine food webs has been challenged after the discovery that they produce secondary metabolites, such as polyunsaturated aldehydes (PUAs), which negatively affect the reproductive success of many invertebrates. Here, we report the effects of two common diatom PUAs, heptadienal and octadienal, which have never been tested before at the molecular level, using the sea urchin, Paracentrotus lividus, as a model organism. We show that both PUAs are able to induce teratogenesis (i.e., malformations), as already reported for decadienal, the better-studied PUA of this group. Moreover, post-recovery experiments show that embryos can recover after treatment with all three PUAs, indicating that negative effects depend both on PUA concentrations and the exposure time of the embryos to these metabolites. We also identify the time range during which PUAs exert the greatest effect on sea urchin embryogenesis. Finally, we report the expression levels of thirty one genes (having a key role in a broad range of functional responses, such as stress, development, differentiation, skeletogenesis and detoxification processes) in order to identify the common targets affected by PUAs and their correlation with morphological abnormalities. This study opens new perspectives for understanding how marine organisms afford protection from environmental toxicants through an integrated network of genes.

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“…The N-terminal “arm” of the V domain binds the actin-binding protein, cortactin [ 51 ]; the C-terminal “arm” of the domain binds viral LYPX 2 S 40 L [ 28 , 29 ]. Filopodia-like structures can result when cortactin is recruited by Alix to the cell periphery and there induces polymerization of cortical actin through Rho family GTPase signaling [ 52 - 56 ]. As Alix associates with both cortactin and Gag through the V domain, it is possible that the enhanced Gag-Alix binding resulting from the S40F mutation promotes formation of the filopodia-like structures in regions of the membrane where L domain-2-mediates VLP formation.…”

Section: Discussionmentioning

confidence: 99%

The S40 residue in HIV-1 Gag p6 impacts local and distal budding determinants, revealing additional late domain activities

et al. 2013

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BackgroundHIV-1 budding is directed primarily by two motifs in Gag p6 designated as late domain-1 and −2 that recruit ESCRT machinery by binding Tsg101 and Alix, respectively, and by poorly characterized determinants in the capsid (CA) domain. Here, we report that a conserved Gag p6 residue, S40, impacts budding mediated by all of these determinants.ResultsWhereas budding normally results in formation of single spherical particles ~100 nm in diameter and containing a characteristic electron-dense conical core, the substitution of Phe for S40, a change that does not alter the amino acids encoded in the overlapping pol reading frame, resulted in defective CA-SP1 cleavage, formation of strings of tethered particles or filopodia-like membrane protrusions containing Gag, and diminished infectious particle formation. The S40F-mediated release defects were exacerbated when the viral-encoded protease (PR) was inactivated or when L domain-1 function was disrupted or when budding was almost completely obliterated by the disruption of both L domain-1 and −2. S40F mutation also resulted in stronger Gag-Alix interaction, as detected by yeast 2-hybrid assay. Reducing Alix binding by mutational disruption of contact residues restored single particle release, implicating the perturbed Gag-Alix interaction in the aberrant budding events. Interestingly, introduction of S40F partially rescued the negative effects on budding of CA NTD mutations EE75,76AA and P99A, which both prevent membrane curvature and therefore block budding at an early stage.ConclusionsThe results indicate that the S40 residue is a novel determinant of HIV-1 egress that is most likely involved in regulation of a critical assembly event required for budding in the Tsg101-, Alix-, Nedd4- and CA N-terminal domain affected pathways.

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Identification and characterization ofPlAlix, theAlix homologue from theMediterranean sea urchinParacentrotus lividus

Cited by 5 publications

References 41 publications

First Morphological and Molecular Evidence of the Negative Impact of Diatom-Derived Hydroxyacids on the Sea UrchinParacentrotus lividus

First Morphological and Molecular Evidence of the Negative Impact of Diatom-Derived Hydroxyacids on the Sea UrchinParacentrotus lividus

Molecular Response to Toxic Diatom-Derived Aldehydes in the Sea Urchin Paracentrotus lividus

The S40 residue in HIV-1 Gag p6 impacts local and distal budding determinants, revealing additional late domain activities

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