This entry include a group of proteins involved in chromatin remodelling, including Vps72 (vacuolar protein sorting-associated protein 72) from budding yeasts. Vps72 is a Htz1-binding component of the SWR1 complex, which is required for the incorporation of the histone variant H2AZ into chromatin []. It is also required for vacuolar protein sorting in budding yeasts [].The Vps72 homologue from animals, YL-1, is a deposition-and-exchange histone chaperone specific for H2AZ1, specifically chaperones H2AZ1 and deposits it into nucleosomes. It is component of the SRCAP and Tip60 complexes, and mediates the ATP-dependent exchange of histone H2AZ1/H2B dimers for nucleosomal H2A/H2B, leading to transcriptional regulation of selected genes by chromatin remodeling [, ].
This entry include a group of proteins involved in chromatin remodelling, including Vps72 (vacuolar protein sorting-associated protein 72) from budding yeasts. Vps72 is a Htz1-binding component of the SWR1 complex, which is required for the incorporation of the histone variant H2AZ into chromatin []. It is also required for vacuolar protein sorting in budding yeasts [].The Vps72 homologue from animals, YL-1, is a deposition-and-exchangehistone chaperone specific for H2AZ1, specifically chaperones H2AZ1 and deposits it into nucleosomes. It is component of the SRCAP and Tip60 complexes, and mediates the ATP-dependent exchange of histone H2AZ1/H2B dimers for nucleosomal H2A/H2B, leading to transcriptional regulation of selected genes by chromatin remodeling [, ].This is the N-terminal region from Vps72/YL1, which covers the aspartate- and glutamate-rich N-terminal domain and the central DNA-binding domain [, ].
Th SWR1 complex is involved in chromatin-remodelling by promoting the the ATP-dependent exchange of histone H2A for the H2A variant HZT1 in Saccharomyces cerevisiae (Baker's yeast) or H2AZ in mammals. The SWR1 chromatin-remodelling complex is composed of at least 14 subunits and has a molecular mass of about 1.2 to 1.5 MDa. In S. cerevisiae the core conserved subunits are: ATPase; Swr1.RuvB-like; Rvb1 and Rvb2.Actin; Act1.Actin-related: Arp4 and Arp6.YEATS protein []; Yaf9.The non-conserved subunits are: Vps71 (Swc6), Vps72 (Swc2), Swc3, Swc4, Swc5, Swc7, Bdf1 [].Seven of the SWR1 subunits are involved in maintaining complex integrity and H2AZ histone replacement activity: Swr1, Swc2, Swc3, Arp6, Swc5, Yaf9 and Swc6. Arp4 is required for the association of Bdf1, Yaf9, and Swc4 and Arp4 is also required for SWR1 H2AZ histone replacement activity in vitro. Furthermore the N-terminal region of the ATPase Swr1 provides the platform upon which Bdf1, Swc7, Arp4, Act1, Yaf9 and Swc4 associate []; it also contains an additional H2AZ-H2B specific binding site, distinct from the binding site of the Swc2 subunit []. In eukaryotes the deposition of variant histones into nucleosomes by the chromatin-remodelling complexes such as the SWR1 and INO80 complexes have many crucial functions including the control of gene regulation and expression, checkpoint regulation, DNA replication and repair, telomer maintenance and chromosomal segregation and as such represent critical components of pathways that maintain genomic integrity. This entry represents the subunit Swc7; the smallestsubunit of the SWR1 complex. Swc7 is not required for H2AZ binding. Swc7 associates with the N terminus of Swr1, and the association of Bdf1 requires Swc7, Yaf9, and Arp4 [].
