Biology subjects

Shidlovskii, Y.

Publications and source records attributed to Shidlovskii, Y..

3 recordsLinked to original sources

bioRxiv2024

The Enhanced Activation of Innate Immunity in Drosophila S2 Cells by Micrococcus luteus is Mediated by Relish

The IMD and Toll signaling pathways in Drosophila melanogaster mediate the innate immune responses to Gram-negative and Gram-positive bacteria and fungi, respectively. Here we studied the involvement of the NF-{kappa}B transcription factor Relish, which is a mediator of the IMD pathway, in the humoral immune response to the Gram-positive bacteria Micrococcus luteus and Bacillus subtilis and the entomopathogenic fungus Metarhizium anisopliae, using D. melanogaster S2 cells as a model. Activation of Relish proteolysis was observed after S2 cell treatment with the control Gram-negative bacterium Escherichia coli. We found that M. luteus had also a noticeable effect on Relish activation, while B. subtilis and M. anisopliae effects were modest. Activation patterns of the genes encoding predominantly the IMD-pathway-dependent antimicrobial peptides (AMPs) and peptidoglycan recognition proteins (PGRPs), as well as the levels of Relish recruitment to the promoters of the genes, were found to be very similar in S2 cells treated with E. coli or M. luteus but were lower and differed in the case of B. subtilis and M. anisopliae. A Relish knockdown (KD) decreased the induction levels observed for all AMP and some PGRP genes in response to M. luteus treatment and the induction levels observed for several AMP genes after M. anisopliae and B. subtilis exposures. Therefore, our findings suggest that Relish plays a critical role in inducing the humoral immune response in Drosophila S2 cells, contributing primarily to the response against M. luteus and, to a lesser extent, to the responses against B. subtilis and M. anisopliae.

molecular biology↗

bioRxiv2022

The insulating activity of the Drosophila BX-C chromatin boundary Fub-1 is parasegmentally regulated by lncRNA read-through

Though long non-coding RNAs (lncRNAs) represent a substantial fraction of the Pol II transcripts in multicellular animals, only a few have known functions. Here we report that the blocking activity of the Bithorax complex (BX-C) Fub-1 boundary is segmentally regulated by its own lncRNA. The Fub-1 boundary is located between the Ultrabithorax (Ubx) gene and the bxd/pbx regulatory domain, which is responsible for regulating Ubx expression in parasegment PS6/segment A1. Fub-1 consists of two hypersensitive sites, HS1 and HS2. HS1 is an insulator while HS2 functions primarily as a lncRNA promoter. To activate Ubx expression in PS6/A1 enhancers in the bxd/pbx domain must be able to bypass Fub-1 blocking activity. We show that expression of the Fub-1 lncRNAs in PS6/A1 from the HS2 promoter inactivates Fub-1 insulating activity. Inactivation is due to readthrough as the HS2 promoter must be directed towards HS1 to disrupt blocking.

molecular biology↗

bioRxiv2020

The 3UTR of the orb2 gene encoding the Drosophila CPEB translation factor plays a critical role in spermatogenesis

CPEB proteins are conserved translation regulators involved in multiple biological processes. One of these proteins in Drosophila, Orb2, is a principal player in spermatogenesis. It is required for meiosis and spermatid differentiation. During the later process orb2 mRNAs and proteins are localized within the developing spermatid. To evaluate the role of orb2 mRNA 3UTR in spermatogenesis, we used the CRISPR/Cas9 system to generate a deletion of the orb2 3UTR, orb2R. This deletion disrupts the process of spermatid differentiation, but has no apparent effect on meiosis. While this deletion appears to destabilize the orb2 mRNA and reduce the levels of Orb2 protein, this is not the primary cause of the differentiation defects. Instead, differentiation appears to be disrupted because orb2 mRNAs and proteins are not properly localized within the differentiating spermatids. Other transcripts and proteins involved in spermatogenesis are also mislocalized in orb2R spermatids. Author summaryThe conserved family of cytoplasmic polyadenylation element binding (CPEB) proteins can activate or repress translation of target mRNAs, depending on the specific biological context, through interaction with special cytoplasmic polyadenylation element (CPE) sequences. These proteins function mainly in highly polarized cells. Orb2, one of the two Drosophila melanogaster CPEB proteins, is predominantly expressed in the testes and is crucial for spermatogenesis. The 3UTR of orb2 transcript contains multiple CPE-like motifs, which is indicative of orb2 self-regulation. We have generated a deletion that removes the greater portion of 3UTR. While this deletion causes a reduction in the levels of orb2 mRNA and the protein, this does not appear to be responsible for the defects in spermatogenesis observed in the deletion mutant. Instead, it is the mislocalization of the mRNA and protein in the developing spermatids.

developmental biology↗