The BAF chromatin remodeling complexes: structure, function, and synthetic lethalities

2021 ◽  
Author(s):  
Julia Varga ◽  
Marie Kube ◽  
Katja Luck ◽  
Sandra Schick
Keyword(s):  
Large Scale ◽  
Treatment Modalities ◽  
Chromatin Remodelers ◽  
Baf Complex ◽  
Synthetic Lethal ◽  
Physiological Processes ◽  
Molecular Action ◽  
Synthetic Lethal Interactions ◽  
Chromatin Remodeling Complexes ◽  
And Function

BAF complexes are multi-subunit chromatin remodelers, which have a fundamental role in genomic regulation. Large-scale sequencing efforts have revealed frequent BAF complex mutations in many human diseases, particularly in cancer and neurological disorders. These findings not only underscore the importance of the BAF chromatin remodelers in cellular physiological processes, but urge a more detailed understanding of their structure and molecular action to enable the development of targeted therapeutic approaches for diseases with BAF complex alterations. Here, we review recent progress in understanding the composition, assembly, structure, and function of BAF complexes, and the consequences of their disease-associated mutations. Furthermore, we highlight intra-complex subunit dependencies and synthetic lethal interactions, which have emerged as promising treatment modalities for BAF-related diseases.

scholarly journals GBAF, a small BAF sub-complex with big implications: a systematic review

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Sarah M. Innis ◽  
Birgit Cabot
Keyword(s):  
Chromatin Remodeling ◽  
Cellular Differentiation ◽  
Complex Function ◽  
Therapeutic Interventions ◽  
Mammalian Development ◽  
Aberrant Expression ◽  
Chromatin Remodelers ◽  
Baf Complex ◽  
Chromatin Remodeling Complexes ◽  
Histone Modifying Enzymes

Abstract ATP-dependent chromatin remodeling by histone-modifying enzymes and chromatin remodeling complexes is crucial for maintaining chromatin organization and facilitating gene transcription. In the SWI/SNF family of ATP-dependent chromatin remodelers, distinct complexes such as BAF, PBAF, GBAF, esBAF and npBAF/nBAF are of particular interest regarding their implications in cellular differentiation and development, as well as in various diseases. The recently identified BAF subcomplex GBAF is no exception to this, and information is emerging linking this complex and its components to crucial events in mammalian development. Furthermore, given the essential nature of many of its subunits in maintaining effective chromatin remodeling function, it comes as no surprise that aberrant expression of GBAF complex components is associated with disease development, including neurodevelopmental disorders and numerous malignancies. It becomes clear that building upon our knowledge of GBAF and BAF complex function will be essential for advancements in both mammalian reproductive applications and the development of more effective therapeutic interventions and strategies. Here, we review the roles of the SWI/SNF chromatin remodeling subcomplex GBAF and its subunits in mammalian development and disease.

Functional diversity of ISWI complexes

2004 ◽  
Vol 82 (4) ◽  
pp. 482-489 ◽  
Author(s):  
Sara S Dirscherl ◽  
Jocelyn E Krebs
Keyword(s):  
Chromatin Remodeling ◽  
Catalytic Core ◽  
Chromatin Remodelers ◽  
Form And Function ◽  
Curr Opin Cell Biol ◽  
Chromatid Cohesion ◽  
Chromatin Remodeling Complexes ◽  
And Function ◽  
Diverse Groups ◽  
Nuclear Processes

The yeast SWI/SNF ATP-dependent chromatin remodeling complex was first identified and characterized over 10 years ago (F. Winston and M. Carlson. 1992. Trends Genet. 8: 387–391.) Since then, the number of distinct ATP-dependent chromatin remodeling complexes and the variety of roles they play in nuclear processes have become dizzying (J.A. Martens and F. Winston. 2003. Curr. Opin. Genet. Dev. 13: 136–142; A. Vacquero et al. 2003. Sci. Aging Knowledge Environ. 2003: RE4) — and that does not even include the companion suite of histone modifying enzymes, which exhibit a comparable diversity in both number of complexes and variety of functions (M.J. Carrozza et al. 2003. Trends Genet. 19: 321–329; W. Fischle et al. 2003. Curr. Opin. Cell Biol. 15: 172–183; M. Iizuka and M.M. Smith. 2003. Curr. Opin. Genet. Dev. 13: 1529–1539). This vast complexity is hardly surprising, given that all nuclear processes that involve DNA — transcription, replication, repair, recombination, sister chromatid cohesion, etc. — must all occur in the context of chromatin. The SWI/SNF-related ATP-dependent remodelers are divided into a number of subfamilies, all related by the SWI2/SNF2 ATPase at their catalytic core. In nearly every species where researchers have looked for them, one or more members of each subfamily have been identified. Even the budding yeast, with its comparatively small genome, contains eight different chromatin remodelers in five different subfamilies. This review will focus on just one subfamily, the Imitation Switch (ISWI) family, which is proving to be one of the most diverse groups of chromatin remodelers in both form and function.

scholarly journals Biochemical and genetic analysis of Ecm14, a conserved fungal pseudopeptidase

2020 ◽  
Author(s):  
R Christian McDonald ◽  
Matthew J Schott ◽  
Temitope A Idowu ◽  
Peter J Lyons
Keyword(s):  
Enzyme Activity ◽  
Large Scale ◽  
Structure And Function ◽  
Activation Mechanism ◽  
Marker Genes ◽  
Synthetic Lethal ◽  
Fungal Process ◽  
And Function

Abstract Background. Like most major enzyme families, the M14 family of metallocarboxypeptidases (MCPs) contains a number of pseudoenzymes predicted to lack enzyme activity and with poorly characterized molecular function. The genome of the yeast Saccharomyces cerevisiae encodes one member of the M14 MCP family, a pseudoenzyme named Ecm14 proposed to function in the extracellular matrix. In order to better understand the function of such pseudoenzymes, we studied the structure and function of Ecm14 in S. cerevisiae. Results. A phylogenetic analysis of Ecm14 in fungi found it to be conserved throughout the ascomycete phylum, with a group of related pseudoenzymes found in basidiomycetes. To investigate the structure and function of this conserved protein, His6-tagged Ecm14 was overexpressed in Sf9 cells and purified. The prodomain of Ecm14 was cleaved in vivo and in vitro by endopeptidases, suggesting an activation mechanism; however, no activity was detectable using standard carboxypeptidase substrates. In order to determine the function of Ecm14 using an unbiased screen, we undertook a synthetic lethal assay. Upon screening approximately 27,000 yeast colonies, twenty-two putative synthetic lethal clones were identified. Further analysis showed many to be synthetic lethal with auxotrophic marker genes and requiring multiple mutations, suggesting that there are few, if any, single S. cerevisiae genes that present synthetic lethal interactions with ecm14Δ. Conclusions. We show in this study that Ecm14, although lacking detectable enzyme activity, is a conserved carboxypeptidase-like protein that is secreted from cells and is processed to a mature form by the action of an endopeptidase. Our study and datasets from other recent large-scale screens suggest a role for Ecm14 in processes such as vesicle-mediated transport and aggregate invasion, a fungal process that has been selected against in modern laboratory strains of S. cerevisiae.

scholarly journals Invariant U2 RNA sequences bordering the branchpoint recognition region are essential for interaction with yeast SF3a and SF3b subunits.

1996 ◽  
Vol 16 (3) ◽  
pp. 818-828 ◽  
Author(s):  
D Yan ◽  
M Ares
Keyword(s):  
Yeast Cells ◽  
Small Nuclear Rna ◽  
Recognition Sequence ◽  
Rna Sequences ◽  
Synthetic Lethal ◽  
U2 Snrna ◽  
U6 Snrna ◽  
Synthetic Lethal Interactions ◽  
Protein Components ◽  
And Function

U2 small nuclear RNA (snRNA) contains a sequence (GUAGUA) that pairs with the intron branchpoint during splicing. This sequence is contained within a longer invariant sequence of unknown secondary structure and function that extends between U2 and I and stem IIa. A part of this region has been proposed to pair with U6 in a structure called helix III. We made mutations to test the function of these nucleotides in yeast U2 snRNA. Most single base changes cause no obvious growth defects; however, several single and double mutations are lethal or conditional lethal and cause a block before the first step of splicing. We used U6 compensatory mutations to assess the contribution of helix III and found that if it forms, helix III is dispensable for splicing in Saccharomyces cerevisiae. On the other hand, mutations in known protein components of the splicing apparatus suppress or enhance the phenotypes of mutations within the invariant sequence that connect the branchpoint recognition sequence to stem IIa. Lethal mutations in the region are suppressed by Cus1-54p, a mutant yeast splicing factor homologous to a mammalian SF3b subunit. Synthetic lethal interactions show that this region collaborates with the DEAD-box protein Prp5p and the yeast SF3a subunits Prp9p, Prp11p, and Prp21p. Together, the data show that the highly conserved RNA element downstream of the branchpoint recognition sequence of U2 snRNA in yeast cells functions primarily with the proteins that make up SF3 rather than with U6 snRNA.

scholarly journals Single-cell genomics reveals the genetic and molecular bases for escape from mutational epistasis in myeloid neoplasms

Blood ◽  
2020 ◽  
Vol 136 (13) ◽  
pp. 1477-1486 ◽  
Author(s):  
Justin Taylor ◽  
Xiaoli Mi ◽  
Khrystyna North ◽  
Moritz Binder ◽  
Alexander Penson ◽  
...  
Keyword(s):  
Single Cell ◽  
Rna Splicing ◽  
Large Scale ◽  
Hematologic Malignancies ◽  
Splicing Factor ◽  
Splicing Factors ◽  
Synthetic Lethal ◽  
Myeloid Neoplasms ◽  
Sequencing Studies ◽  
Synthetic Lethal Interactions

Abstract Large-scale sequencing studies of hematologic malignancies have revealed notable epistasis among high-frequency mutations. One of the most striking examples of epistasis occurs for mutations in RNA splicing factors. These lesions are among the most common alterations in myeloid neoplasms and generally occur in a mutually exclusive manner, a finding attributed to their synthetic lethal interactions and/or convergent effects. Curiously, however, patients with multiple-concomitant splicing factor mutations have been observed, challenging our understanding of one of the most common examples of epistasis in hematologic malignancies. In this study, we performed bulk and single-cell analyses of patients with myeloid malignancy who were harboring ≥2 splicing factor mutations, to understand the frequency and basis for the coexistence of these mutations. Although mutations in splicing factors were strongly mutually exclusive across 4231 patients (q < .001), 0.85% harbored 2 concomitant bona fide splicing factor mutations, ∼50% of which were present in the same individual cells. However, the distribution of mutations in patients with double mutations deviated from that in those with single mutations, with selection against the most common alleles, SF3B1K700E and SRSF2P95H/L/R, and selection for less common alleles, such as SF3B1 non-K700E mutations, rare amino acid substitutions at SRSF2P95, and combined U2AF1S34/Q157 mutations. SF3B1 and SRSF2 alleles enriched in those with double-mutations had reduced effects on RNA splicing and/or binding compared with the most common alleles. Moreover, dual U2AF1 mutations occurred in cis with preservation of the wild-type allele. These data highlight allele-specific differences as critical in regulating the molecular effects of splicing factor mutations as well as their cooccurrences/exclusivities with one another.

scholarly journals Biochemical and genetic analysis of Ecm14, a conserved fungal pseudopeptidase

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
R. Christian McDonald ◽  
Matthew J. Schott ◽  
Temitope A. Idowu ◽  
Peter J. Lyons
Keyword(s):  
Enzyme Activity ◽  
Large Scale ◽  
Structure And Function ◽  
Activation Mechanism ◽  
Marker Genes ◽  
Synthetic Lethal ◽  
Fungal Process ◽  
And Function

Abstract Background Like most major enzyme families, the M14 family of metallocarboxypeptidases (MCPs) contains a number of pseudoenzymes predicted to lack enzyme activity and with poorly characterized molecular function. The genome of the yeast Saccharomyces cerevisiae encodes one member of the M14 MCP family, a pseudoenzyme named Ecm14 proposed to function in the extracellular matrix. In order to better understand the function of such pseudoenzymes, we studied the structure and function of Ecm14 in S. cerevisiae. Results A phylogenetic analysis of Ecm14 in fungi found it to be conserved throughout the ascomycete phylum, with a group of related pseudoenzymes found in basidiomycetes. To investigate the structure and function of this conserved protein, His6-tagged Ecm14 was overexpressed in Sf9 cells and purified. The prodomain of Ecm14 was cleaved in vivo and in vitro by endopeptidases, suggesting an activation mechanism; however, no activity was detectable using standard carboxypeptidase substrates. In order to determine the function of Ecm14 using an unbiased screen, we undertook a synthetic lethal assay. Upon screening approximately 27,000 yeast colonies, twenty-two putative synthetic lethal clones were identified. Further analysis showed many to be synthetic lethal with auxotrophic marker genes and requiring multiple mutations, suggesting that there are few, if any, single S. cerevisiae genes that present synthetic lethal interactions with ecm14Δ. Conclusions We show in this study that Ecm14, although lacking detectable enzyme activity, is a conserved carboxypeptidase-like protein that is secreted from cells and is processed to a mature form by the action of an endopeptidase. Our study and datasets from other recent large-scale screens suggest a role for Ecm14 in processes such as vesicle-mediated transport and aggregate invasion, a fungal process that has been selected against in modern laboratory strains of S. cerevisiae.

554 Identification of Synthetic Lethal Interactions with Oncogenic Ras Through Large Scale Functional Genomic Screening

2012 ◽  
Vol 48 ◽  
pp. 170
Author(s):  
R.L. Beijersbergen ◽  
J. Vidal-Rodriguez ◽  
C. Lieftink ◽  
K. De Lint ◽  
J. Poell ◽  
...  
Keyword(s):  
Large Scale ◽  
Functional Genomic ◽  
Synthetic Lethal ◽  
Oncogenic Ras ◽  
Genomic Screening ◽  
Synthetic Lethal Interactions

scholarly journals Biochemical and genetic analysis of Ecm14, a conserved fungal pseudopeptidase

2020 ◽  
Author(s):  
R Christian McDonald ◽  
Matthew J Schott ◽  
Temitope A Idowu ◽  
Peter J Lyons
Keyword(s):  
Enzyme Activity ◽  
Large Scale ◽  
Structure And Function ◽  
Activation Mechanism ◽  
Marker Genes ◽  
Synthetic Lethal ◽  
Fungal Process ◽  
And Function

Abstract Background. Like most major enzyme families, the M14 family of metallocarboxypeptidases (MCPs) contains a number of pseudoenzymes predicted to lack enzyme activity and with poorly characterized molecular function. The genome of the yeast S. cerevisiae encodes one member of the M14 MCP family, a pseudoenzyme named Ecm14 proposed to function in the extracellular matrix. In order to better understand the function of such pseudoenzymes, we studied the structure and function of Ecm14 in S. cerevisiae. Results. A phylogenetic analysis of Ecm14 in fungi found it to be conserved throughout the ascomycete phylum, with a group of related pseudoenzymes found in basidiomycetes. To investigate the structure and function of this conserved protein, his6-tagged Ecm14 was overexpressed in Sf9 cells and purified. The prodomain of Ecm14 was cleaved in vivo and in vitro by endopeptidases, suggesting an activation mechanism; however, no activity was detectable using standard carboxypeptidase substrates. In order to determine the function of Ecm14 using an unbiased screen, we undertook a synthetic lethal assay. Upon screening approximately 27,000 yeast colonies, twenty-two putative synthetic lethal clones were identified. Further analysis showed many to be synthetic lethal with auxotrophic marker genes and requiring multiple mutations, suggesting that there are few, if any, single S. cerevisiae genes that present synthetic lethal interactions with ecm14. Conclusions. We show in this study that Ecm14, although lacking detectable enzyme activity, is a conserved carboxypeptidase-like protein that is secreted from cells and is processed to a mature form by the action of an endopeptidase. Our study and datasets from other recent large-scale screens suggest a role for Ecm14 in processes such as vesicle-mediated transport and aggregate invasion, a fungal process that has been selected against in modern laboratory strains of S. cerevisiae.

scholarly journals Targeting Cancer at the Intersection of Signaling and Epigenetics

2019 ◽  
Vol 3 (1) ◽  
pp. 365-384
Author(s):  
Stephanie Guerra ◽  
Karen Cichowski
Keyword(s):  
Large Scale ◽  
Human Cancer ◽  
Biological Response ◽  
Specific Drug ◽  
Epigenetic Alterations ◽  
Synthetic Lethal ◽  
Epigenetic State ◽  
Synthetic Lethal Interactions ◽  
A Cell ◽  
Chronic Activation

While mutations resulting in the chronic activation of signaling pathways drive human cancer, the epigenetic state of a cell ultimately dictates the biological response to any given oncogenic signal. Moreover, large-scale genomic sequencing efforts have now identified a plethora of mutations in chromatin regulatory genes in human tumors, which can amplify, modify, or complement traditional oncogenic events. Nevertheless, the co-occurrence of oncogenic and epigenetic defects appears to create novel therapeutic vulnerabilities, which can be targeted by specific drug combinations. Here we discuss general mechanisms by which oncogenic and epigenetic alterations cooperate in human cancer and synthesize the field's early efforts in developing promising therapeutic combinations. Collectively, these studies reveal common themes underlying potential chemical synthetic lethal interactions and support both the expansion and refinement of this type of therapeutic approach.

scholarly journals ASTER: A Method to Predict Clinically Actionable Synthetic Lethal Interactions

2020 ◽  
Author(s):  
Herty Liany ◽  
Anand Jeyasekharan ◽  
Vaibhav Rajan
Keyword(s):  
Hypothesis Testing ◽  
Large Scale ◽  
Multiple Hypothesis Testing ◽  
Statistical Hypothesis ◽  
Breast Cancers ◽  
Statistical Hypothesis Testing ◽  
Synthetic Lethal ◽  
Synthetic Lethal Interactions ◽  
A New Technique ◽  
Disease Free

AbstractA Synthetic Lethal (SL) interaction is a functional relationship between two genes or functional entities where the loss of either entity is viable but the loss of both is lethal. Such pairs can be used to develop targeted anticancer therapies with fewer side effects and reduced overtreatment. However, finding clinically actionable SL interactions remains challenging. Leveraging large-scale unified gene expression data of both disease-free and cancerous data, we design a new technique, based on statistical hypothesis testing, called ASTER (Analysis of Synthetic lethality by comparison with Tissue-specific disease-free gEnomic and tRanscriptomic data) to identify SL pairs. For large-scale multiple hypothesis testing, we develop an extension called ASTER++ that can utilize additional input gene features within the hypothesis testing framework. Our extensive experiments demonstrate the efficacy of ASTER in accurately identifying SL pairs that are therapeutically actionable in stomach and breast cancers.

Sign in / Sign up

Export Citation Format

Share Document