Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

MicroRNA profiling by array of Sinorhizobium meliloti grown under heat, cold, acidic, basic, oxidative and salt stress in time course.

ABSTRACT: Identification and expression profiling of stress induced (heat and cold shock, acidic, basic, oxidative and saline stress) and non stress induced (Logarithmic and stationary phase) sRNAs by oligonucleotide microarray: In these microarray hybridizations, signals derived from fractions composed of small (<200 nt) and long (>200 nt) RNAs were compared. This strategy allowed for identifying sequence regions predominantly present in the small RNA fraction excluding sequence regions that were also represented in the long RNA fraction at a considerable level. Applying a cut-off of ? 8 to the ratio of signals derived from the small RNA to signals from the long RNA fraction were determined as putative small noncoding RNAs.

ORGANISM(S): Sinorhizobium meliloti

SUBMITTER: Jan-Philip Schlueter

PROVIDER: E-MTAB-204 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Co-translational N-terminal (Nt-) acetylation of nascent polypeptides is catalyzed by N-terminal acetyltransferases (NATs). The very N-terminal amino acid sequence is the major factor determining whether or not a given protein is Nt-acetylated. In humans, six different NATs, denoted NatA-NatF, are identified. In the current study we used N-terminal COFRADIC analysis to define the in vivo substrate specificity of Naa50 (Nat5)/NatE as this has long remained elusive. Three yeast strains were generated; a control strain endogenously expressing yNaa50, a deletion strain depleted of yNaa50 and a strain deleted of yNaa50 but ectopically expressing human Naa50. When comparing the Nt-acetylation status of different N-termini in the control strain with the deletion strain, a reduction in Nt-acetylation for several yeast proteins was observed. To our surprise, these substrates were not of the predicted NatE-type substrates, but rather canonical NatA substrates. Further, ectopic expression of hNaa50 mainly resulted in the Nt-acetylation of a selected class of otherwise Nt-free yeast N-termini besides increasing the degree of Nt-acetylation of several other yeast proteins, and as such (partially) complementing those N-termini displaying reduced Nt-acetylation upon yNAA50-deletion. The preferred substrates of hNaa50 were predominantly Met-starting N-termini including Met-Lys-, Met-Val-, Met-Ala-, Met-Tyr-, Met-Phe-, Met-Leu-, Met-Ser- and Met-Thr, and highly overlapped with the previously identified human Naa60/NatF substrate specificity profile. Identification of several hNaa50 substrates with a small amino acid in the second position also revealed a potential interplay between the NATs and methionine aminopeptidases (MetAPs). The initiator Methionine (iMet) is normally cleaved off by MetAPs when the second amino acid is small, but our in vitro data suggest that in contrast to a free iMet, an Nt-acetylated iMet is not hydrolyzed by MetAPs. Thus, Naa50-mediated Nt-acetylation may potentially act as a mechanism to retain the iMet of proteins with a small amino acid at the second position that normally would be hydrolyzed.

Project description:We previously reported widespread differential expression of long non-protein-coding RNAs (ncRNAs) in response to virus infection. Here, we expanded the study through small RNA transcriptome sequencing analysis of the host response to both severe acute respiratory syndrome coronavirus (SARS-CoV) and influenza virus infections across four founder mouse strains of the Collaborative Cross, a recombinant inbred mouse resource for mapping complex traits. We observed differential expression of over 200 small RNAs of diverse classes during infection. A majority of identified microRNAs (miRNAs) showed divergent changes in expression across mouse strains with respect to SARS-CoV and influenza virus infections and responded differently to a highly pathogenic reconstructed 1918 virus compared to a minimally pathogenic seasonal influenza virus isolate. Novel insights into miRNA expression changes, including the association with pathogenic outcomes and large differences between in vivo and in vitro experimental systems, were further elucidated by a survey of selected miRNAs across diverse virus infections. The small RNAs identified also included many non-miRNA small RNAs, such as small nucleolar RNAs (snoRNAs), in addition to nonannotated small RNAs. An integrative sequencing analysis of both small RNAs and long transcripts from the same samples showed that the results revealing differential expression of miRNAs during infection were largely due to transcriptional regulation and that the predicted miRNA-mRNA network could modulate global host responses to virus infection in a combinatorial fashion. These findings represent the first integrated sequencing analysis of the response of host small RNAs to virus infection and show that small RNAs are an integrated component of complex networks involved in regulating the host response to infection. IMPORTANCE: Most studies examining the host transcriptional response to infection focus only on protein-coding genes. However, mammalian genomes transcribe many short and long non-protein-coding RNAs (ncRNAs). With the advent of deepsequencing technologies, systematic transcriptome analysis of the host response, including analysis of ncRNAs of different sizes, is now possible. Using this approach, we recently discovered widespread differential expression of host long (>200 nucleotide[nt]) ncRNAs in response to virus infection. Here, the samples described in the previous report were again used, but we sequenced another fraction of the transcriptome to study very short (about 20 to 30 nt) ncRNAs. We demonstrated that virus infection also altered expression of many short ncRNAs of diverse classes. Putting the results of the two studies together, we show that small RNAs may also play an important role in regulating the host response to virus infection.

Dataset Information

MicroRNA profiling by array of Sinorhizobium meliloti grown under heat, cold, acidic, basic, oxidative and salt stress in time course.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets