ABSTRACT: The SUMO E3 ligase-like proteins PIAL1 and PIAL2 interact with MOM1 and form a novel complex required for transcriptional silencing [RNA-seq]
Project description:The mechanism by which MORPHEUS'MOLECULE1 (MOM1) contributes to transcriptional gene silencing remained elusive since the gene was first identified and characterized (Amedeo et al., 2000). Here, we report that two PIAS (PROTEIN INHIBITOR OF ACTIVATED STAT)-type SUMO E3 ligase-like proteins PIAL1 and PIAL2 function redundantly to mediate transcriptional silencing at MOM1 target loci. PIAL1 and PIAL2 physically interact with each other and with MOM1 to form a high-molecular-weight complex. In the absence of either PIAL2 or MOM1, the formation of the high-molecular-weight complex was disrupted. We identified a previously uncharacterized IND (interacting domain) in PIAL1 and PIAL2, and demonstrated that IND directly interacts with MOM1. The CMM2 (conserved MOM1 motif 2) domain of MOM1 was previously shown to be required for the dimerization of MOM1. We demonstrated that the CMM2 domain is also required for the interaction of MOM1 with PIAL1 and PIAL2. We found that although PIAL2 has a SUMO E3 ligase activity, the activity is dispensable for PIAL2 in transcriptional silencing. This study suggests that PIAL1 and PIAl2 act as components of the MOM1-containing complex to mediate transcriptional silencing at heterochromatin regions.
Project description:The mechanism by which MORPHEUS'MOLECULE1 (MOM1) contributes to transcriptional gene silencing remained elusive since the gene was first identified and characterized (Amedeo et al., 2000). Here, we report that two PIAS (PROTEIN INHIBITOR OF ACTIVATED STAT)-type SUMO E3 ligase-like proteins PIAL1 and PIAL2 function redundantly to mediate transcriptional silencing at MOM1 target loci. PIAL1 and PIAL2 physically interact with each other and with MOM1 to form a high-molecular-weight complex. In the absence of either PIAL2 or MOM1, the formation of the high-molecular-weight complex was disrupted. We identified a previously uncharacterized IND (interacting domain) in PIAL1 and PIAL2, and demonstrated that IND directly interacts with MOM1. The CMM2 (conserved MOM1 motif 2) domain of MOM1 was previously shown to be required for the dimerization of MOM1. We demonstrated that the CMM2 domain is also required for the interaction of MOM1 with PIAL1 and PIAL2. We found that although PIAL2 has a SUMO E3 ligase activity, the activity is dispensable for PIAL2 in transcriptional silencing. This study suggests that PIAL1 and PIAl2 act as components of the MOM1-containing complex to mediate transcriptional silencing at heterochromatin regions.
Project description:The SUMO E3 ligase-like proteins PIAL1 and PIAL2 interact with MOM1 and form a novel complex required for transcriptional silencing
Project description:The SUMO E3 ligase-like proteins PIAL1 and PIAL2 interact with MOM1 and form a novel complex required for transcriptional silencing [Bisulfite-seq]
Project description:mRNA profiling of WI38 wild-type or overexpressiong the SUMO E3 ligase PIASy in human primary fibroblasts 24h post-infection. The goal of this study is to analyse transcriptional changes in cells over-expressing the SUMO E3 ligase PIASy and to compare them with ChIPseq data for several histones marks and proteins of the SUMO machinery including PIASy
Project description:The budding yeast E3 SUMO ligase Mms21, a component of the Smc5-6 complex, regulates sister chromatid cohesion, DNA replication, and DNA repair. We identify a role for Mms21 in ribosome biogenesis. The mms21RINGD mutant exhibits reduced rRNA production, nuclear accumulation of 60S and 40S ribosomal proteins, and elevated Gcn4 translation. Genes involved in ribosome biogenesis and translation are down-regulated in the mms21RINGD mutant. Examining gene expression profile of mms21RINGD mutant compared to wild-type by RNA Seq using Ilumina sequencing
Project description:The chromatin organizers Satb1 and Satb2 regulate developmental genes in a tissue- and locus-specific manner. In mouse Embryonic Stem Cells (mESCs), the Satb proteins are involved in the balance between pluripotency and differentiation by direct control of key developmental factors such as Nanog and a number of Hox genes. Despite their structural similarities, the Satb proteins regulate mESC pluripotency in opposing ways: Satb1 promotes differentiation by repressing Nanog and activating the neural genes Bcl2 and Nestin, while Satb2 supports the pluripotent state by activating Nanog and repressing Satb1. To further address the mechanisms by which the Satb proteins regulate gene expression, we examined the conjugation of Satb2 with the small ubiquitin-like modifier (SUMO) in pluripotent and differentiated mESCs. We describe for the first time the endogenous SUMOylation of Satb2 in mESCs as a response to developmental cues. We found that Satb2 is progressively SUMO2-modified during differentiation of ESCs towards ectodermal precursors. Moreover, we identified Zfp451 as a SUMO E3 ligase able to interact with and modify Satb2 with SUMO2 in vitro and in vivo. Ablation of Zfp451 or mutation of the SUMO-acceptor lysines in the Satb2 protein disrupt the ability of mESCs to efficiently shut-down pluripotency genes and activate the differentiation program. Importantly, forced expression of SUMO2-Satb2 N-terminal fusions rescues the differentiation defect of SUMO-Satb2 deficient mESCs. Mechanistically, SUMOylation reduces binding of Satb2 to a subset of loci associated to pluripotency genes and changes the composition of Satb2-containing complexes in chromatin. Taken together, our data suggests that SUMO modification of the chromatin organizer Satb2 by the E3 ligase Zfp451 is required for the efficient downregulation of pluripotency genes and initiation of the differentiation program in mouse embryonic stem cells.
Project description:The chromatin organizers Satb1 and Satb2 regulate developmental genes in a tissue- and locus-specific manner. In mouse Embryonic Stem Cells (mESCs), the Satb proteins are involved in the balance between pluripotency and differentiation by direct control of key developmental factors such as Nanog and a number of Hox genes. Despite their structural similarities, the Satb proteins regulate mESC pluripotency in opposing ways: Satb1 promotes differentiation by repressing Nanog and activating the neural genes Bcl2 and Nestin, while Satb2 supports the pluripotent state by activating Nanog and repressing Satb1. To further address the mechanisms by which the Satb proteins regulate gene expression, we examined the conjugation of Satb2 with the small ubiquitin-like modifier (SUMO) in pluripotent and differentiated mESCs. We describe for the first time the endogenous SUMOylation of Satb2 in mESCs as a response to developmental cues. We found that Satb2 is progressively SUMO2-modified during differentiation of ESCs towards ectodermal precursors. Moreover, we identified Zfp451 as a SUMO E3 ligase able to interact with and modify Satb2 with SUMO2 in vitro and in vivo. Ablation of Zfp451 or mutation of the SUMO-acceptor lysines in the Satb2 protein disrupt the ability of mESCs to efficiently shut-down pluripotency genes and activate the differentiation program. Importantly, forced expression of SUMO2-Satb2 N-terminal fusions rescues the differentiation defect of SUMO-Satb2 deficient mESCs. Mechanistically, SUMOylation reduces binding of Satb2 to a subset of loci associated to pluripotency genes and changes the composition of Satb2-containing complexes in chromatin. Taken together, our data suggests that SUMO modification of the chromatin organizer Satb2 by the E3 ligase Zfp451 is required for the efficient downregulation of pluripotency genes and initiation of the differentiation program in mouse embryonic stem cells.
Project description:The chromatin organizers Satb1 and Satb2 regulate developmental genes in a tissue- and locus-specific manner. In mouse Embryonic Stem Cells (mESCs), the Satb proteins are involved in the balance between pluripotency and differentiation by direct control of key developmental factors such as Nanog and a number of Hox genes. Despite their structural similarities, the Satb proteins regulate mESC pluripotency in opposing ways: Satb1 promotes differentiation by repressing Nanog and activating the neural genes Bcl2 and Nestin, while Satb2 supports the pluripotent state by activating Nanog and repressing Satb1. To further address the mechanisms by which the Satb proteins regulate gene expression, we examined the conjugation of Satb2 with the small ubiquitin-like modifier (SUMO) in pluripotent and differentiated mESCs. We describe for the first time the endogenous SUMOylation of Satb2 in mESCs as a response to developmental cues. We found that Satb2 is progressively SUMO2-modified during differentiation of ESCs towards ectodermal precursors. Moreover, we identified Zfp451 as a SUMO E3 ligase able to interact with and modify Satb2 with SUMO2 in vitro and in vivo. Ablation of Zfp451 or mutation of the SUMO-acceptor lysines in the Satb2 protein disrupt the ability of mESCs to efficiently shut-down pluripotency genes and activate the differentiation program. Importantly, forced expression of SUMO2-Satb2 N-terminal fusions rescues the differentiation defect of SUMO-Satb2 deficient mESCs. Mechanistically, SUMOylation reduces binding of Satb2 to a subset of loci associated to pluripotency genes and changes the composition of Satb2-containing complexes in chromatin. Taken together, our data suggests that SUMO modification of the chromatin organizer Satb2 by the E3 ligase Zfp451 is required for the efficient downregulation of pluripotency genes and initiation of the differentiation program in mouse embryonic stem cells.
Project description:The budding yeast E3 SUMO ligase Mms21, a component of the Smc5-6 complex, regulates sister chromatid cohesion, DNA replication, and DNA repair. We identify a role for Mms21 in ribosome biogenesis. The mms21RINGD mutant exhibits reduced rRNA production, nuclear accumulation of 60S and 40S ribosomal proteins, and elevated Gcn4 translation. Genes involved in ribosome biogenesis and translation are down-regulated in the mms21RINGD mutant.