The RNA-Binding Protein SBR (Dm NXF1) Is Required for the Constitution of Medulla Boundaries in Drosophila melanogaster Optic Lobes.

Ludmila Mamon,Daria Kopytova,Anna Yakimova,Elena Golubkova

doi:10.3390/cells10051144

Ludmila Mamon, Daria Kopytova + Show 2 more

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https://doi.org/10.3390/cells10051144

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Journal: Cells	Publication Date: May 10, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: St Petersburg University, Russian Academy of Sciences

Abstract

Drosophila melanogaster sbr (small bristles) is an orthologue of the Nxf1 (nuclear export factor 1) genes in different Opisthokonta. The known function of Nxf1 genes is the export of various mRNAs from the nucleus to the cytoplasm. The cytoplasmic localization of the SBR protein indicates that the nuclear export function is not the only function of this gene in Drosophila. RNA-binding protein SBR enriches the nucleus and cytoplasm of specific neurons and glial cells. In sbr12 mutant males, the disturbance of medulla boundaries correlates with the defects of photoreceptor axons pathfinding, axon bundle individualization, and developmental neurodegeneration. RNA-binding protein SBR participates in processes allowing axons to reach and identify their targets.

Highlights

Enriches the nucleus and cytoplasm of specific neurons and glial cells
The best known function of the Nxf1 genes is the transport of various mRNAs from the nucleus to the cytoplasm [1]
NXF1 is localized in the nucleus or the nuclear envelope according to its function [4]

Summary

Introduction

Enriches the nucleus and cytoplasm of specific neurons and glial cells. In sbr mutant males, the disturbance of medulla boundaries correlates with the defects of photoreceptor axons pathfinding, axon bundle individualization, and developmental neurodegeneration. As we have shown previously, D. melanogaster SBR (Dm NXF1) is located in the nucleus and in the cytoplasm of different cells [5,6,7]. This finding suggests that the SBR protein has specific cytoplasmic functions in addition to its participation in nuclear export of mRNAs. In the Drosophila larval brain, SBR forms granules in the neuron bodies and neurites [7]. Others are marked by either FMR1 or SBR These observations suggest that SBR has specific localized RNA targets in the cytoplasm [8].

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