TY - JOUR
T1 - Dynamic interactions of the homologous pairing 2 (Hop2)–meiotic nuclear divisions 1 (Mnd1) protein complex with meiotic presynaptic filaments in budding yeast
AU - Brooks Crickard, J.
AU - Kwon, Youngho
AU - Sung, Patrick
AU - Greene, Eric C.
N1 - Funding Information:
This research was supported by National Institutes of Health Grants R35 GM118026 (to E. C. G.), R01 ES007061, RO1 CA220123, and P30 CA054174 (to P. S.), and PO1 CA092584 (to E. C. G. and P. S.) and National Science Foundation (NSF) Grant MCB1154511 (to E. C. G.). The authors declare they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Funding Information:
1A Fellow of The Mark Foundation for Cancer Research for the Damon-Run-yon Cancer Research Foundation (Grant DRG 2310-17).
PY - 2019/1/11
Y1 - 2019/1/11
N2 - Homologous recombination (HR) is a universally conserved DNA repair pathway that can result in the exchange of genetic material. In eukaryotes, HR has evolved into an essential step in meiosis. During meiosis many eukaryotes utilize a two-recombinase pathway. This system consists of Rad51 and the meiosis-specific recombinase Dmc1. Both recombinases have distinct activities during meiotic HR, despite being highly similar in sequence and having closely related biochemical activities, raising the question of how these two proteins can perform separate functions. A likely explanation for their differential regulation involves the meiosis-specific recombination proteins Hop2 and Mnd1, which are part of a highly conserved eukaryotic protein complex that participates in HR, albeit through poorly understood mechanisms. To better understand how Hop2–Mnd1 functions during HR, here we used DNA curtains in conjunction with single-molecule imaging to measure and quantify the binding of the Hop2–Mnd1 complex from Saccharomyces cerevisiae to recombination intermediates comprising Rad51– and Dmc1–ssDNA in real time. We found that yeast Hop2–Mnd1 bound rapidly to Dmc1–ssDNA filaments with high affinity and remained bound for 1.3 min before dissociating. We also observed that this binding interaction was highly specific for Dmc1 and found no evidence for an association of Hop2–Mnd1 with Rad51–ssDNA or RPA–ssDNA. Our findings provide new quantitative insights into the binding dynamics of Hop2–Mnd1 with the meiotic presynaptic complex. On the basis of these findings, we propose a model in which recombinase specificities for meiotic accessory proteins enhance separation of the recombinases’ functions during meiotic HR.
AB - Homologous recombination (HR) is a universally conserved DNA repair pathway that can result in the exchange of genetic material. In eukaryotes, HR has evolved into an essential step in meiosis. During meiosis many eukaryotes utilize a two-recombinase pathway. This system consists of Rad51 and the meiosis-specific recombinase Dmc1. Both recombinases have distinct activities during meiotic HR, despite being highly similar in sequence and having closely related biochemical activities, raising the question of how these two proteins can perform separate functions. A likely explanation for their differential regulation involves the meiosis-specific recombination proteins Hop2 and Mnd1, which are part of a highly conserved eukaryotic protein complex that participates in HR, albeit through poorly understood mechanisms. To better understand how Hop2–Mnd1 functions during HR, here we used DNA curtains in conjunction with single-molecule imaging to measure and quantify the binding of the Hop2–Mnd1 complex from Saccharomyces cerevisiae to recombination intermediates comprising Rad51– and Dmc1–ssDNA in real time. We found that yeast Hop2–Mnd1 bound rapidly to Dmc1–ssDNA filaments with high affinity and remained bound for 1.3 min before dissociating. We also observed that this binding interaction was highly specific for Dmc1 and found no evidence for an association of Hop2–Mnd1 with Rad51–ssDNA or RPA–ssDNA. Our findings provide new quantitative insights into the binding dynamics of Hop2–Mnd1 with the meiotic presynaptic complex. On the basis of these findings, we propose a model in which recombinase specificities for meiotic accessory proteins enhance separation of the recombinases’ functions during meiotic HR.
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U2 - 10.1074/jbc.RA118.006146
DO - 10.1074/jbc.RA118.006146
M3 - Article
C2 - 30420424
AN - SCOPUS:85059831295
VL - 294
SP - 490
EP - 501
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 2
ER -