RESUMO
In response to transcription-blocking DNA damage, cells orchestrate a multi-pronged reaction, involving transcription-coupled DNA repair, degradation of RNA polymerase II (RNAPII), and genome-wide transcription shutdown. Here, we provide insight into how these responses are connected by the finding that ubiquitylation of RNAPII itself, at a single lysine (RPB1 K1268), is the focal point for DNA-damage-response coordination. K1268 ubiquitylation affects DNA repair and signals RNAPII degradation, essential for surviving genotoxic insult. RNAPII degradation results in a shutdown of transcriptional initiation, in the absence of which cells display dramatic transcriptome alterations. Additionally, regulation of RNAPII stability is central to transcription recovery-persistent RNAPII depletion underlies the failure of this process in Cockayne syndrome B cells. These data expose regulation of global RNAPII levels as integral to the cellular DNA-damage response and open the intriguing possibility that RNAPII pool size generally affects cell-specific transcription programs in genome instability disorders and even normal cells.
Assuntos
Dano ao DNA , RNA Polimerase II/metabolismo , Reparo do DNA , Células HEK293 , Humanos , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Transcrição Gênica , Ubiquitinação , Raios UltravioletaRESUMO
The multisubunit Mediator, comprising â¼30 distinct proteins, plays an essential role in gene expression regulation by acting as a bridge between DNA-binding transcription factors and the RNA polymerase II (RNAPII) transcription machinery. Efforts to uncover the Mediator mechanism have been hindered by a poor understanding of its structure, subunit organization, and conformational rearrangements. By overcoming biochemical and image analysis hurdles, we obtained accurate EM structures of yeast and human Mediators. Subunit localization experiments, docking of partial X-ray structures, and biochemical analyses resulted in comprehensive mapping of yeast Mediator subunits and a complete reinterpretation of our previous Mediator organization model. Large-scale Mediator rearrangements depend on changes at the interfaces between previously described Mediator modules, which appear to be facilitated by factors conducive to transcription initiation. Conservation across eukaryotes of Mediator structure, subunit organization, and RNA polymerase II interaction suggest conservation of fundamental aspects of the Mediator mechanism.
Assuntos
Complexo Mediador/química , Complexo Mediador/ultraestrutura , Microscopia Crioeletrônica , Células HeLa , Humanos , Complexo Mediador/metabolismo , Modelos Moleculares , Mapeamento de Interação de Proteínas , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Transcriptional regulation in eukaryotes depends on a complex network of interactions between RNA polymerases and a host of transcription factors and coregulators that control their activity during transcription initiation and elongation. Among these are an enormous variety of enzymes and proteins that modulate chromatin structure via changes in DNA methylation, histone modifications, and nucleosome location. This volume of the Annual Review of Biochemistry contains a set of four reviews addressing the interplay between mechanisms that regulate DNA methylation, chromatin structure, and transcription.
Assuntos
Cromatina/metabolismo , Epigênese Genética , Transcrição Gênica , Animais , Células Eucarióticas/metabolismo , HumanosRESUMO
Gene duplication and divergence is a major driver in the emergence of evolutionary novelties. How variations in amino acid sequences lead to loss of ancestral activity and functional diversification of proteins is poorly understood. We used cross-species functional analysis of Drosophila Labial and its mouse HOX1 orthologs (HOXA1, HOXB1, and HOXD1) as a paradigm to address this issue. Mouse HOX1 proteins display low (30%) sequence similarity with Drosophila Labial. However, substituting endogenous Labial with the mouse proteins revealed that HOXA1 has retained essential ancestral functions of Labial, while HOXB1 and HOXD1 have diverged. Genome-wide analysis demonstrated similar DNA-binding patterns of HOXA1 and Labial in mouse cells, while HOXB1 binds to distinct targets. Compared with HOXB1, HOXA1 shows an enrichment in co-occupancy with PBX proteins on target sites and exists in the same complex with PBX on chromatin. Functional analysis of HOXA1-HOXB1 chimeric proteins uncovered a novel six-amino-acid C-terminal motif (CTM) flanking the homeodomain that serves as a major determinant of ancestral activity. In vitro DNA-binding experiments and structural prediction show that CTM provides an important domain for interaction of HOXA1 proteins with PBX. Our findings show that small changes outside of highly conserved DNA-binding regions can lead to profound changes in protein function.
Assuntos
Motivos de Aminoácidos/genética , Proteínas de Drosophila/genética , Evolução Molecular , Proteínas de Homeodomínio/genética , Animais , Drosophila melanogaster/classificação , Drosophila melanogaster/genética , Estudo de Associação Genômica Ampla , Camundongos , Modelos Moleculares , Ligação Proteica/genética , Domínios Proteicos , Relação Estrutura-AtividadeRESUMO
The human epigenetic cell-cycle regulator HCF-1 undergoes an unusual proteolytic maturation process resulting in stably associated HCF-1(N) and HCF-1(C) subunits that regulate different aspects of the cell cycle. Proteolysis occurs at six centrally located HCF-1(PRO)-repeat sequences and is important for activation of HCF-1(C)-subunit functions in M phase progression. We show here that the HCF-1(PRO) repeat is recognized by O-linked ß-N-acetylglucosamine transferase (OGT), which both O-GlcNAcylates the HCF-1(N) subunit and directly cleaves the HCF-1(PRO) repeat. Replacement of the HCF-1(PRO) repeats by a heterologous proteolytic cleavage signal promotes HCF-1 proteolysis but fails to activate HCF-1(C)-subunit M phase functions. These results reveal an unexpected role of OGT in HCF-1 proteolytic maturation and an unforeseen nexus between OGT-directed O-GlcNAcylation and proteolytic maturation in HCF-1 cell-cycle regulation.
Assuntos
Fator C1 de Célula Hospedeira/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Ciclo Celular , Glicosilação , Fator C1 de Célula Hospedeira/química , Fator C1 de Célula Hospedeira/genética , Humanos , Dados de Sequência Molecular , Mutação , Subunidades Proteicas/metabolismo , Alinhamento de SequênciaRESUMO
Promoter-proximal pausing by initiated RNA polymerase II (Pol II) and regulated release of paused polymerase into productive elongation has emerged as a major mechanism of transcription activation. Reactivation of paused Pol II correlates with recruitment of super-elongation complexes (SECs) containing ELL/EAF family members, P-TEFb, and other proteins, but the mechanism of their recruitment is an unanswered question. Here, we present evidence for a role of human Mediator subunit MED26 in this process. We identify in the conserved N-terminal domain of MED26 overlapping docking sites for SEC and a second ELL/EAF-containing complex, as well as general initiation factor TFIID. In addition, we present evidence consistent with the model that MED26 can function as a molecular switch that interacts first with TFIID in the Pol II initiation complex and then exchanges TFIID for complexes containing ELL/EAF and P-TEFb to facilitate transition of Pol II into the elongation stage of transcription.
Assuntos
Transativadores/metabolismo , Transcrição Gênica , Fatores de Elongação da Transcrição/metabolismo , Proliferação de Células , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP70/metabolismo , Células HeLa , Humanos , Complexo Mediador , Fosforilação , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Polimerase II/metabolismoRESUMO
In a recent publication in Science, Kujirai et al. (2018) use single-particle cryo-EM to resolve several Pol II-nucleosome interactions, shedding new light on transcription elongation in a native chromatin environment.
Assuntos
Nucleossomos , RNA Polimerase II , Cromatina , Microscopia Crioeletrônica , Transcrição GênicaRESUMO
The bZIP transcription factor ATF6α is a master regulator of endoplasmic reticulum (ER) stress response genes. In this report, we identify the multifunctional RNA polymerase II transcription factor Elongin as a cofactor for ATF6α-dependent transcription activation. Biochemical studies reveal that Elongin functions at least in part by facilitating ATF6α-dependent loading of Mediator at the promoters and enhancers of ER stress response genes. Depletion of Elongin from cells leads to impaired transcription of ER stress response genes and to defects in the recruitment of Mediator and its CDK8 kinase subunit. Taken together, these findings bring to light a role for Elongin as a loading factor for Mediator during the ER stress response.
Assuntos
Fator 6 Ativador da Transcrição/metabolismo , Elonguina/metabolismo , Estresse do Retículo Endoplasmático , Regulação da Expressão Gênica , Complexo Mediador/metabolismo , RNA Polimerase II/metabolismo , Fator 6 Ativador da Transcrição/genética , Animais , Elonguina/genética , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/patologia , Células HeLa , Humanos , Complexo Mediador/genética , Regiões Promotoras Genéticas , RNA Polimerase II/genética , Ratos , Transdução de Sinais , Ativação TranscricionalRESUMO
The SNF2 family ATPase Amplified in Liver Cancer 1 (ALC1) is the only chromatin remodeling enzyme with a poly(ADP-ribose) (PAR) binding macrodomain. ALC1 functions together with poly(ADP-ribose) polymerase PARP1 to remodel nucleosomes. Activation of ALC1 cryptic ATPase activity and the subsequent nucleosome remodeling requires binding of its macrodomain to PAR chains synthesized by PARP1 and NAD+ A key question is whether PARP1 has a role(s) in ALC1-dependent nucleosome remodeling beyond simply synthesizing the PAR chains needed to activate the ALC1 ATPase. Here, we identify PARP1 separation-of-function mutants that activate ALC1 ATPase but do not support nucleosome remodeling by ALC1. Investigation of these mutants has revealed multiple functions for PARP1 in ALC1-dependent nucleosome remodeling and provides insights into its multifaceted role in chromatin remodeling.
Assuntos
DNA Helicases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Nucleossomos/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Linhagem Celular Tumoral , Montagem e Desmontagem da Cromatina , Reparo do DNA , HumanosRESUMO
The conserved Mediator co-activator complex has an essential role in the regulation of RNA polymerase II transcription in all eukaryotes. Understanding the structure and interactions of Mediator is crucial for determining how the complex influences transcription initiation and conveys regulatory information to the basal transcription machinery. Here we present a 4.4 Å resolution cryo-electron microscopy map of Schizosaccharomyces pombe Mediator in which conserved Mediator subunits are individually resolved. The essential Med14 subunit works as a central backbone that connects the Mediator head, middle and tail modules. Comparison with a 7.8 Å resolution cryo-electron microscopy map of a Mediator-RNA polymerase II holoenzyme reveals that changes in the structure of Med14 facilitate a large-scale Mediator rearrangement that is essential for holoenzyme formation. Our study suggests that access to different conformations and crosstalk between structural elements are essential for the Mediator regulation mechanism, and could explain the capacity of the complex to integrate multiple regulatory signals.
Assuntos
Complexo Mediador/química , Complexo Mediador/metabolismo , RNA Polimerase II/química , RNA Polimerase II/ultraestrutura , Sítios de Ligação , Microscopia Crioeletrônica , Holoenzimas/química , Holoenzimas/metabolismo , Holoenzimas/ultraestrutura , Complexo Mediador/ultraestrutura , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , RNA Polimerase II/metabolismo , Schizosaccharomyces , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/ultraestrutura , Relação Estrutura-AtividadeRESUMO
The Elongin complex was originally identified as an RNA polymerase II (RNAPII) elongation factor and subsequently as the substrate recognition component of a Cullin-RING E3 ubiquitin ligase. More recent evidence indicates that the Elongin ubiquitin ligase assembles with the Cockayne syndrome B helicase (CSB) in response to DNA damage and can target stalled polymerases for ubiquitylation and removal from the genome. In this report, we present evidence that the CSB-Elongin ubiquitin ligase pathway has roles beyond the DNA damage response in the activation of RNAPII-mediated transcription. We observed that assembly of the CSB-Elongin ubiquitin ligase is induced not just by DNA damage, but also by a variety of signals that activate RNAPII-mediated transcription, including endoplasmic reticulum (ER) stress, amino acid starvation, retinoic acid, glucocorticoids, and doxycycline treatment of cells carrying several copies of a doxycycline-inducible reporter. Using glucocorticoid receptor (GR)-regulated genes as a model, we showed that glucocorticoid-induced transcription is accompanied by rapid recruitment of CSB and the Elongin ubiquitin ligase to target genes in a step that depends upon the presence of transcribing RNAPII on those genes. Consistent with the idea that the CSB-Elongin pathway plays a direct role in GR-regulated transcription, mouse cells lacking the Elongin subunit Elongin A exhibit delays in both RNAPII accumulation on and dismissal from target genes following glucocorticoid addition and withdrawal, respectively. Taken together, our findings bring to light a new role for the CSB-Elongin pathway in RNAPII-mediated transcription.
Assuntos
DNA Helicases/genética , Enzimas Reparadoras do DNA/genética , Elonguina/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Polimerase II/genética , Ubiquitina-Proteína Ligases/genética , Animais , Síndrome de Cockayne/enzimologia , Síndrome de Cockayne/genética , DNA Helicases/química , DNA Helicases/ultraestrutura , Reparo do DNA/genética , Enzimas Reparadoras do DNA/química , Enzimas Reparadoras do DNA/ultraestrutura , Elonguina/química , Elonguina/ultraestrutura , Humanos , Camundongos , Complexos Multiproteicos/química , Complexos Multiproteicos/genética , Complexos Multiproteicos/ultraestrutura , Proteínas de Ligação a Poli-ADP-Ribose/química , Proteínas de Ligação a Poli-ADP-Ribose/ultraestrutura , RNA Polimerase II/química , Receptores de Glucocorticoides/química , Receptores de Glucocorticoides/genética , Ubiquitina/química , Ubiquitina/genética , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/ultraestrutura , Ubiquitinação/genéticaRESUMO
Elongin A binds to Elongins B and C to form the RNA polymerase II transcription elongation factor Elongin. It also functions as the substrate recognition subunit of a ubiquitin ligase that is formed by binding of Elongin to Cullin protein CUL5 and RING finger protein RBX2 and that targets RNA polymerase II for ubiquitination. In this article, we describe use of acceptor photobleaching fluorescence resonance energy transfer (AP-FRET) and laser microirradiation-based assays to study regulated assembly of the Elongin ubiquitin ligase and its recruitment to regions of localized DNA damage.
Assuntos
Dano ao DNA , Elonguina/metabolismo , Transferência Ressonante de Energia de Fluorescência/métodos , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Culina/metabolismo , DNA/metabolismo , DNA/efeitos da radiação , Eucariotos/enzimologia , Eucariotos/metabolismo , LasersRESUMO
ELL family transcription factors activate the overall rate of RNA polymerase II (Pol II) transcription elongation by binding directly to Pol II and suppressing its tendency to pause. In metazoa, ELL regulates Pol II transcription elongation as part of a large multisubunit complex referred to as the Super Elongation Complex (SEC), which includes P-TEFb and EAF, AF9 or ENL, and an AFF family protein. Although orthologs of ELL and EAF have been identified in lower eukaryotes including Schizosaccharomyces pombe, it has been unclear whether SEC-like complexes function in lower eukaryotes. In this report, we describe isolation from S. pombe of an ELL-containing complex with features of a rudimentary SEC. This complex includes S. pombe Ell1, Eaf1, and a previously uncharacterized protein we designate Ell1 binding protein 1 (Ebp1), which is distantly related to metazoan AFF family members. Like the metazoan SEC, this S. pombe ELL complex appears to function broadly in Pol II transcription. Interestingly, it appears to have a particularly important role in regulating genes involved in cell separation.
Assuntos
RNA Polimerase II/genética , Proteínas de Schizosaccharomyces pombe/genética , Fatores de Transcrição/genética , Fatores de Elongação da Transcrição/genética , Fator B de Elongação Transcricional Positiva/química , Fator B de Elongação Transcricional Positiva/genética , RNA Polimerase II/química , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/química , Fatores de Transcrição/química , Transcrição Gênica , Fatores de Elongação da Transcrição/químicaRESUMO
Elongin A performs dual functions as the transcriptionally active subunit of RNA polymerase II (Pol II) elongation factor Elongin and as the substrate recognition subunit of a Cullin-RING E3 ubiquitin ligase that ubiquitylates Pol II in response to DNA damage. Assembly of the Elongin A ubiquitin ligase and its recruitment to sites of DNA damage is a tightly regulated process induced by DNA-damaging agents and α-amanitin, a drug that induces Pol II stalling. In this study, we demonstrate (i) that Elongin A and the ubiquitin ligase subunit CUL5 associate in cells with the Cockayne syndrome B (CSB) protein and (ii) that this interaction is also induced by DNA-damaging agents and α-amanitin. In addition, we present evidence that the CSB protein promotes stable recruitment of the Elongin A ubiquitin ligase to sites of DNA damage. Our findings are consistent with the model that the Elongin A ubiquitin ligase and the CSB protein function together in a common pathway in response to Pol II stalling and DNA damage.
Assuntos
Dano ao DNA , DNA Helicases/metabolismo , Enzimas Reparadoras do DNA/metabolismo , RNA Polimerase II/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Alfa-Amanitina/metabolismo , Linhagem Celular , Proteínas Culina/metabolismo , Reparo do DNA , Elonguina , Transferência Ressonante de Energia de Fluorescência , Proteínas de Fluorescência Verde/metabolismo , Humanos , Processamento de Imagem Assistida por Computador , Mutação , Plasmídeos/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose , Fatores de Transcrição/genéticaRESUMO
The human males absent on the first (MOF)-containing histone acetyltransferase nonspecific lethal (NSL) complex comprises nine subunits including the O-linked N-acetylglucosamine (O-GlcNAc) transferase, isoform 1 (OGT1). However, whether the O-GlcNAc transferase activity of OGT1 controls histone acetyltransferase activity of the NSL complex and whether OGT1 physically interacts with the other NSL complex subunits remain unclear. Here, we demonstrate that OGT1 regulates the activity of the NSL complex by mainly acetylating histone H4 Lys-16, Lys-5, and Lys-8 via O-GlcNAcylation and stabilization of the NSL complex subunit NSL3. Knocking down or overexpressing OGT1 in human cells remarkably affected the global acetylation of histone H4 residues Lys-16, Lys-5, and Lys-8. Because OGT1 is a subunit of the NSL complex, we also investigated the function of OGT1 in this complex. Co-transfection/co-immunoprecipitation experiments combined with in vitro O-GlcNAc transferase assays confirmed that OGT1 specifically binds to and O-GlcNAcylates NSL3. In addition, wheat germ agglutinin affinity purification verified the occurrence of O-GlcNAc modification on NSL3 in cells. Moreover, O-GlcNAcylation of NSL3 by wild-type OGT1 (OGT1-WT) stabilized NSL3. This stabilization was lost after co-transfection of NSL3 with an OGT1 mutant, OGT1C964A, that lacks O-GlcNAc transferase activity. Furthermore, stabilization of NSL3 by OGT1-WT significantly increased the global acetylation levels of H4 Lys-5, Lys-8, and Lys-16 in cells. These results suggest that OGT1 regulates the activity of the NSL complex by stabilizing NSL3.
Assuntos
Histona Acetiltransferases/metabolismo , Histonas/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Proteínas Nucleares/metabolismo , Processamento de Proteína Pós-Traducional , Acetilação , Substituição de Aminoácidos , Animais , Células HEK293 , Células HeLa , Histona Acetiltransferases/antagonistas & inibidores , Histona Acetiltransferases/química , Histona Acetiltransferases/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , N-Acetilglucosaminiltransferases/antagonistas & inibidores , N-Acetilglucosaminiltransferases/química , N-Acetilglucosaminiltransferases/genética , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/química , Proteínas Nucleares/genética , Mutação Puntual , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estabilidade Proteica , Subunidades Proteicas/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Interferência de RNA , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Células Sf9 , Spodoptera , Especificidade por SubstratoRESUMO
Chromosomal translocations involving the MLL gene are associated with infant acute lymphoblastic and mixed lineage leukemia. There are a large number of translocation partners of MLL that share very little sequence or seemingly functional similarities; however, their translocations into MLL result in the pathogenesis of leukemia. To define the molecular reason why these translocations result in the pathogenesis of leukemia, we purified several of the commonly occurring MLL chimeras. We have identified super elongation complex (SEC) associated with all chimeras purified. SEC includes ELL, P-TEFb, AFF4, and several other factors. AFF4 is required for SEC stability and proper transcription by poised RNA polymerase II in metazoans. Knockdown of AFF4 in leukemic cells shows reduction in MLL chimera target gene expression, suggesting that AFF4/SEC could be a key regulator in the pathogenesis of leukemia through many of the MLL partners.
Assuntos
Leucemia/genética , Proteína de Leucina Linfoide-Mieloide/genética , Fator B de Elongação Transcricional Positiva/metabolismo , Proteínas Repressoras/fisiologia , Fatores de Elongação da Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Células HeLa , Resposta ao Choque Térmico , Histona-Lisina N-Metiltransferase , Proteínas Homeobox A10 , Proteínas de Homeodomínio/metabolismo , Humanos , Dados de Sequência Molecular , Proteína de Leucina Linfoide-Mieloide/fisiologia , Interferência de RNA , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Alinhamento de Sequência , Transcrição Gênica , Fatores de Elongação da Transcrição/fisiologia , Translocação GenéticaRESUMO
Mediator plays an integral role in activation of RNA polymerase II (Pol II) transcription. A key step in activation is binding of Mediator to Pol II to form the Mediator-Pol II holoenzyme. Here, we exploit a combination of biochemistry and macromolecular EM to investigate holoenzyme assembly. We identify a subset of human Mediator head module subunits that bind Pol II independent of other subunits and thus probably contribute to a major Pol II binding site. In addition, we show that binding of human Mediator to Pol II depends on the integrity of a conserved "hinge" in the middle module MED21-MED7 heterodimer. Point mutations in the hinge region leave core Mediator intact but lead to increased disorder of the middle module and markedly reduced affinity for Pol II. These findings highlight the importance of Mediator conformation for holoenzyme assembly.
Assuntos
Holoenzimas/metabolismo , Complexo Mediador/metabolismo , RNA Polimerase II/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Holoenzimas/química , Holoenzimas/genética , Humanos , Complexo Mediador/química , Complexo Mediador/genética , Ligação Proteica , Conformação Proteica , RNA Polimerase II/química , RNA Polimerase II/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos , Transcrição GênicaRESUMO
The study of conserved protein interaction networks seeks to better understand the evolution and regulation of protein interactions. Here, we present a quantitative proteomic analysis of 18 orthologous baits from three distinct chromatin-remodeling complexes in Saccharomyces cerevisiae and Homo sapiens. We demonstrate that abundance levels of orthologous proteins correlate strongly between the two organisms and both networks have highly similar topologies. We therefore used the protein abundances in one species to cross-predict missing protein abundance levels in the other species. Lastly, we identified a novel conserved low-abundance subnetwork further demonstrating the value of quantitative analysis of networks.