Project description:The AID (activation induced deaminase)/APOBEC (apolipoprotein B mRNA editing catalytic polypeptide-like) family of proteins are zinc-dependent cytidine deaminases active on polynucleotides and involved in RNA editing, DNA demethylation or DNA editing. The enzymatic activity, substrate or physiological target(s) of APOBEC2, a member of the AID/APOBEC, remain elusive. Here, we combined next generation sequencing (NGS) techniques with state-of-the-art molecular biology to comprehensively examine the physiological effects of APOBEC2 on the transcriptome and methylome using C2C12 myoblasts differentiating in culture. We also examined APOBEC2’s genome wide-binding specificity. Using RNA sequencing (RNA-seq) by polyA capture, we detected no evidence that APOBEC2 is an RNA editor. In the same system, enhanced reduced representation bisulfite sequencing (eRRBS) data did not support the proposed role of APOBEC2 as a 5-methyl-C (5mC) deaminase. However, chromatin immunoprecipitation sequencing (ChIP-Seq) did reveal specific locations of genomic occupancy of APOBEC2 with a specific motif preference. Combining biochemical, ChIP-Seq and RNA-Seq gene expression analyses we demonstrate that APOBEC2 acts as a negative regulator of gene expression in muscle cells. Our data support a model of APOBEC2 acting as a chromatin-binding factor that leads to inhibition of transcription of genes involved in cell cycle regulation during C2C12 differentiation. This SuperSeries is composed of the SubSeries listed below.
Project description:The AID (activation induced deaminase)/APOBEC (apolipoprotein B mRNA editing catalytic polypeptide-like) family of proteins are zinc-dependent cytidine deaminases active on polynucleotides and involved in RNA editing, DNA demethylation or DNA editing. The enzymatic activity, substrate or physiological target(s) of APOBEC2, a member of the AID/APOBEC, remain elusive. Here, we combined next generation sequencing (NGS) techniques with state-of-the-art molecular biology to comprehensively examine the physiological effects of APOBEC2 on the transcriptome and methylome using C2C12 myoblasts differentiating in culture. We also examined APOBEC2’s genome wide-binding specificity. Using RNA sequencing (RNA-seq) by polyA capture, we detected no evidence that APOBEC2 is an RNA editor. In the same system, enhanced reduced representation bisulfite sequencing (eRRBS) data did not support the proposed role of APOBEC2 as a 5-methyl-C (5mC) deaminase. However, chromatin immunoprecipitation sequencing (ChIP-Seq) did reveal specific locations of genomic occupancy of APOBEC2 with a specific motif preference. Combining biochemical, ChIP-Seq and RNA-Seq gene expression analyses we demonstrate that APOBEC2 acts as a negative regulator of gene expression in muscle cells. Our data support a model of APOBEC2 acting as a chromatin-binding factor that leads to inhibition of transcription of genes involved in cell cycle regulation during C2C12 differentiation.
Project description:The AID (activation induced deaminase)/APOBEC (apolipoprotein B mRNA editing catalytic polypeptide-like) family of proteins are zinc-dependent cytidine deaminases active on polynucleotides and involved in RNA editing, DNA demethylation or DNA editing. The enzymatic activity, substrate or physiological target(s) of APOBEC2, a member of the AID/APOBEC, remain elusive. Here, we combined next generation sequencing (NGS) techniques with state-of-the-art molecular biology to comprehensively examine the physiological effects of APOBEC2 on the transcriptome and methylome using C2C12 myoblasts differentiating in culture. We also examined APOBEC2’s genome wide-binding specificity. Using RNA sequencing (RNA-seq) by polyA capture, we detected no evidence that APOBEC2 is an RNA editor. In the same system, enhanced reduced representation bisulfite sequencing (eRRBS) data did not support the proposed role of APOBEC2 as a 5-methyl-C (5mC) deaminase. However, chromatin immunoprecipitation sequencing (ChIP-Seq) did reveal specific locations of genomic occupancy of APOBEC2 with a specific motif preference. Combining biochemical, ChIP-Seq and RNA-Seq gene expression analyses we demonstrate that APOBEC2 acts as a negative regulator of gene expression in muscle cells. Our data support a model of APOBEC2 acting as a chromatin-binding factor that leads to inhibition of transcription of genes involved in cell cycle regulation during C2C12 differentiation.
Project description:The AID (activation induced deaminase)/APOBEC (apolipoprotein B mRNA editing catalytic polypeptide-like) family of proteins are zinc-dependent cytidine deaminases active on polynucleotides and involved in RNA editing, DNA demethylation or DNA editing. The enzymatic activity, substrate or physiological target(s) of APOBEC2, a member of the AID/APOBEC, remain elusive. Here, we combined next generation sequencing (NGS) techniques with state-of-the-art molecular biology to comprehensively examine the physiological effects of APOBEC2 on the transcriptome and methylome using C2C12 myoblasts differentiating in culture. We also examined APOBEC2’s genome wide-binding specificity. Using RNA sequencing (RNA-seq) by polyA capture, we detected no evidence that APOBEC2 is an RNA editor. In the same system, enhanced reduced representation bisulfite sequencing (eRRBS) data did not support the proposed role of APOBEC2 as a 5-methyl-C (5mC) deaminase. However, chromatin immunoprecipitation sequencing (ChIP-Seq) did reveal specific locations of genomic occupancy of APOBEC2 with a specific motif preference. Combining biochemical, ChIP-Seq and RNA-Seq gene expression analyses we demonstrate that APOBEC2 acts as a negative regulator of gene expression in muscle cells. Our data support a model of APOBEC2 acting as a chromatin-binding factor that leads to inhibition of transcription of genes involved in cell cycle regulation during C2C12 differentiation.
Project description:The apolipoprotein B mRNA editing enzyme, catalytic polypeptide (APOBEC) family is comprised of nucleic acid editors with roles ranging from antibody diversification to RNA editing. APOBEC2, a member of this family with an evolutionarily conserved nucleic acid binding cytidine deaminase domain, has neither an established substrate nor function. Using a cellular model of muscle differentiation where APOBEC2 is inducibly expressed, we confirmed that APOBEC2 does not have the attributed molecular functions of the APOBEC family, such as RNA editing, DNA demethylation, and DNA mutation. Instead, we found that during muscle differentiation APOBEC2 occupied a specific motif within promoter regions; its removal from those regions resulted in transcriptional changes. Mechanistically, these changes reflect the direct interaction of APOBEC2 with histone deacetylase (HDAC) transcriptional corepressor complexes. We also found that APOBEC2 could bind DNA directly, in a sequence-specific fashion, suggesting that it functions as a recruiter of HDAC to specific genes whose promoters it occupies. These genes are normally suppressed during muscle cell differentiation and their suppression may contribute to the safeguarding of muscle cell fate. Altogether, our results reveal a novel role for APOBEC2 within the APOBEC family.
Project description:To identify novel transcripts originating from orphan CGIs we isolated RNA from undifferentiated embryonic stem cells (ESCs), ESCs differentiated into embryoid bodies (EBs), and ESCs differentiated into neuronal cells; we also used RNA from mature male mouse brain. RNA Seq data were visually analysed for transcripts originating from orphan CGIs.