Mutations in human survival motor neurons 1 (SMN1) cause spinal muscular atrophy (SMA) and are associated with defects assembly of small nuclear ribonucleoproteins (snRNPs) vitro. However, the etiological link between snRNPs SMA is unclear. We have developed a Drosophila melanogaster system to model vivo. Larval-lethal Smn-null mutations show no detectable snRNP reduction, making it unlikely that these animals die from global deprivation. Hypomorphic Smn reduce dSMN protein levels adult...

Small nuclear ribonucleoproteins (snRNPs) are core components of the spliceosome. The U1, U2, U4, and U5 snRNPs each contain a common set seven Sm proteins. Three these proteins posttranslationally modified to symmetric dimethylarginine (sDMA) residues within their C-terminal tails. However, precise function this modification in snRNP biogenesis pathway is unclear. Several lines evidence suggest that methyltransferase protein arginine 5 (PRMT5) responsible for sDMA We found human cells,...

To evaluate the effects of σ 1 receptor (σR1) agonist, (+)-pentazocine, on lipopolysaccharide (LPS)-induced inflammatory changes in retinal microglia cells.Retinal cells were isolated from Sprague-Dawley rat pups. Cells treated with LPS or without (+)-pentazocine and σR1 antagonist BD1063. Morphologic assayed. Cell viability was assessed by using MTT assay. Supernatant levels tumor necrosis factor α (TNF-α), interleukin 10, (IL-10), monocyte chemoattractant protein-1 (MCP-1), nitric oxide...

The localization of ASH1 mRNA to the distal tip budding yeast cells is essential for proper regulation mating type switching in Saccharomyces cerevisiae. A element that predominantly 3′-untranslated region (UTR) can direct this bud. Using three-hybrid vivo RNA-binding assay, we identified a protein, Loc1p, binds vitro directly wild-type 3′-UTR RNA, but not mutant RNA incapable localizing bud nor several other mRNAs. LOC1 codes novel protein recognizes double-stranded structures and required...

The Drosophila egg chamber provides a useful model for examining mechanisms by which cell fates are specified and maintained in the context of complex tissue. is also an excellent understanding mechanism cytoskeletal filaments organized critical interplay between organization, polarity establishment, fate specification. Previous work has shown that Egalitarian (Egl) required specification maintenance oocyte fate. Mutants egl either completely fail to specify oocyte, or if specified,...

Sm proteins form stable ribonucleoprotein (RNP) complexes with small nuclear (sn)RNAs and are core components of the eukaryotic spliceosome. In vivo, assembly onto snRNAs requires survival motor neurons (SMN) complex. Several reports have shown that SMN protein binds high affinity to symmetric dimethylarginine (sDMA) residues present on C-terminal tails SmB, SmD1, SmD3. This post-translational modification is thought play a crucial role in snRNP assembly. human cells, two distinct arginine...

Recent studies have revealed that diverse cell types use mRNA localization as a means to establish polarity. Despite the prevalence of this phenomenon, much less is known regarding mechanism by which mRNAs are localized. The Drosophila melanogaster oocyte provides useful model for examining process localization. oskar (osk) localized at posterior oocyte, thus restricting expression Oskar protein site. osk microtubule dependent and requires plus-end-directed motor Kinesin-1. Unlike most...

Purpose: To evaluate, in vivo, the effects of sigma-1 receptor (σR1) agonist, (+)-pentazocine, on N-methyl-D-aspartate (NMDA)-mediated retinal excitotoxicity. Methods: Intravitreal NMDA injections were performed C57BL/6J mice (wild type [WT]) and σR1−/− (σR1 knockout [KO]) mice. Fellow eyes injected with phosphate-buffered saline (PBS). An experimental cohort WT σR1 KO was administered (+)-pentazocine by intraperitoneal injection, untreated animals served as controls. Retinas derived from...

Sm and Sm-like proteins are RNA-binding factors found in all three domains of life. Eukaryotic play essential roles pre-mRNA splicing, forming the cores spliceosomal small nuclear ribonucleoproteins (snRNPs). Recently, have been implicated specification germ cells. However, a mechanistic understanding their involvement germline is lacking germline-specific RNA target has not identified. We demonstrate that Drosophila SmB SmD3 specific components oskar messenger ribonucleoprotein (mRNP),...

In order for eukaryotic cells to function properly, they must establish polarity. The Drosophila oocyte uses mRNA localization polarity and hence provides a genetically tractable model in which study this process. spatial restriction of oskar its subsequent protein product is necessary embryonic patterning. requires microtubules microtubule-based motor proteins. Null mutants Kinesin heavy chain (Khc), the subunit plus end-directed Kinesin-1, result delocalization. Although majority particles...

ABSTRACT A conserved mechanism of polarity establishment is the localization mRNA to specific cellular regions. Although it clear that many mRNAs are transported along microtubules, much less known about by which these linked microtubule motors. The RNA binding protein Egalitarian (Egl) necessary for several in Drosophila oocytes and embryos. Egl also interacts with Dynein light chain (Dlc) Bicaudal-D (BicD). role Dlc BicD has remained elusive. Both proteins required oocyte specification, as...

The initial steps of spliceosomal small nuclear ribonucleoprotein (snRNP) maturation take place in the cytoplasm. After formation an Sm-core and a trimethylguanosine (TMG) cap, RNPs are transported into nucleus via import adaptor snurportin1 (SPN) receptor importin-beta. To better understand this process, we identified SPN residues that required to mediate interactions with TMG caps, importin-beta, export receptor, exportin1 (Xpo1/Crm1). Mutation single arginine residue within importin-beta...

Nervous wreck (Nwk) is a conserved F-BAR protein that attenuates synaptic growth and promotes function in Drosophila. In an effort to understand how Nwk carries out its dual roles, we isolated interacting proteins using mass spectrometry. We report interaction between BAR-SH3 sorting nexins, family of membrane-binding implicated diverse intracellular trafficking processes. mammalian cells, nexins induce plasma membrane tubules localize NWK2, consistent with possible functional during the...

In Saccharomyces cerevisiae , ASH1 mRNA is localized to the tip of daughter cells during anaphase cell cycle. localization dependent on four cis -acting elements as well Myo4p, She2p, and She3p. She3p are hypothesized form a heterotrimeric protein complex that directly transports cells. She2p an RNA-binding interacts with associates Here we report identification seven mutants—N36S, R43A, R44A, R52A, R52K, R63A, R63K—that result in delocalization mRNA. These mutants defective for activity but...

The sigma 1 receptor (S1R) is a unique transmembrane protein that has been shown to regulate neuronal differentiation and cellular survival. It expressed within several cell types throughout the nervous system visceral organs, including neurons glia eye. S1R ligands are therapeutic targets for diseases ranging from neurodegenerative conditions neoplastic disorders. However, effects of activation inhibition cells not well characterized. Within eye, astrocytes at optic nerve head crucial...

Abstract Dynactin is a multi-subunit complex that functions as regulator of the Dynein motor. A central component this Dynamitin/p50 (Dmn). Dmn required for endosome motility in mammalian cell lines. However, extent to which participates sorting cargo via endosomal system unknown. In study, we examined endocytic role using Drosophila melanogaster oocyte model. Yolk proteins are internalized into clathrin-mediated endocytosis, trafficked through pathway, and stored condensed yolk granules....

Sigma 1 receptor (S1R) is expressed in retinal ganglion cells (RGCs) and astrocytes, its activation neuroprotective. We evaluated the contribution of S1R within optic nerve head astrocytes (ONHAs) to growth survival RGCs vitro.Wild-type (WT) WT or knockout (S1R KO) ONHAs were cocultured for 2, 4, 7 days. Total maximal neurite length, root, extremity counts measured. Cell death was measured using a TUNEL assay. Signal transducer activator transcription 3 phosphorylation levels ONHA-derived...

RNA localization is a mechanism to post-transcriptionally regulate gene expression. Eukaryotic organisms ranging from fungi mammals localize mRNAs spatially restrict synthesis of specific proteins distinct regions the cytoplasm. In this review, we provide general summary pathways in Saccharomyces cerevisiae, Xenopus, Drosophila and mammalian neurons.

One mechanism by which cells post-transcriptionally regulate gene expression is via intercellular and intracellular sorting of mRNA. In Saccharomyces cerevisiae, the localization ASH1 mRNA to distal tip budding results in asymmetric Ash1p daughter cell nuclei. Efficient depends upon activity four cis-acting elements also trans-factors She2p, She3p, Myo4p. Myo4p have been proposed form an particle. She2p directly specifically binds each elements, whereas She3p has hypothesized function as...

The mammalian Sorting Nexin 9 (Snx9) family consists of three paralogs: Snx9, Snx18 and Snx33. Most the published literature to date has centered on role Snx9 in clathrin-mediated endocytosis (CME). contains an Sh3 domain at its N-terminus been shown interact with Dynamin actin nucleation factors via this domain. In addition domain, also a C-terminal BAR domains are known sense and/or induce membrane curvature. endocytosis, recent studies have implicated diverse processes such as autophagy,...