TY - JOUR
T1 - Biochemical and functional characterization of a meiosis-specific Pch2/ORC AAA+ assembly
AU - Villar-Fernández, María Ascensión
AU - Cardoso da Silva, Richard
AU - Firlej, Magdalena
AU - Pan, Dongqing
AU - Weir, Elisabeth
AU - Sarembe, Annika
AU - Raina, Vivek B
AU - Bange, Tanja
AU - Weir, John R
AU - Vader, Gerben
N1 - © 2020 Villar-Fernández et al.
PY - 2020/11
Y1 - 2020/11
N2 - Pch2 is a meiosis-specific AAA+ protein that controls several important chromosomal processes. We previously demonstrated that Orc1, a subunit of the ORC, functionally interacts with budding yeast Pch2. The ORC (Orc1-6) AAA+ complex loads the AAA+ MCM helicase to origins of replication, but whether and how ORC collaborates with Pch2 remains unclear. Here, we show that a Pch2 hexamer directly associates with ORC during the meiotic G2/prophase. Biochemical analysis suggests that Pch2 uses its non-enzymatic NH2-terminal domain and AAA+ core and likely engages the interface of ORC that also binds to Cdc6, a factor crucial for ORC-MCM binding. Canonical ORC function requires association with origins, but we show here that despite causing efficient removal of Orc1 from origins, nuclear depletion of Orc2 and Orc5 does not trigger Pch2/Orc1-like meiotic phenotypes. This suggests that the function for Orc1/Pch2 in meiosis can be executed without efficient association of ORC with origins of replication. In conclusion, we uncover distinct functionalities for Orc1/ORC that drive the establishment of a non-canonical, meiosis-specific AAA+ assembly with Pch2.
AB - Pch2 is a meiosis-specific AAA+ protein that controls several important chromosomal processes. We previously demonstrated that Orc1, a subunit of the ORC, functionally interacts with budding yeast Pch2. The ORC (Orc1-6) AAA+ complex loads the AAA+ MCM helicase to origins of replication, but whether and how ORC collaborates with Pch2 remains unclear. Here, we show that a Pch2 hexamer directly associates with ORC during the meiotic G2/prophase. Biochemical analysis suggests that Pch2 uses its non-enzymatic NH2-terminal domain and AAA+ core and likely engages the interface of ORC that also binds to Cdc6, a factor crucial for ORC-MCM binding. Canonical ORC function requires association with origins, but we show here that despite causing efficient removal of Orc1 from origins, nuclear depletion of Orc2 and Orc5 does not trigger Pch2/Orc1-like meiotic phenotypes. This suggests that the function for Orc1/Pch2 in meiosis can be executed without efficient association of ORC with origins of replication. In conclusion, we uncover distinct functionalities for Orc1/ORC that drive the establishment of a non-canonical, meiosis-specific AAA+ assembly with Pch2.
KW - Cell Cycle/physiology
KW - Cell Cycle Proteins/genetics
KW - DNA Helicases/genetics
KW - DNA Replication/genetics
KW - G2 Phase Cell Cycle Checkpoints/physiology
KW - Meiosis/genetics
KW - Nuclear Proteins/genetics
KW - Origin Recognition Complex/metabolism
KW - Prophase/physiology
KW - Protein Binding/genetics
KW - Replication Origin/genetics
KW - Saccharomyces cerevisiae/genetics
KW - Saccharomyces cerevisiae Proteins/genetics
KW - Saccharomycetales/genetics
U2 - 10.26508/lsa.201900630
DO - 10.26508/lsa.201900630
M3 - Article
C2 - 32826290
SN - 2575-1077
VL - 3
JO - Life science alliance
JF - Life science alliance
IS - 11
ER -