The Deubiquitinase USP37 Regulates Chromosome Cohesion and Mitotic Progression

Abstract

A bipolar mitotic spindle facilitates the equal segregation of chromosomes to two daughter cells. To achieve bipolar attachment of microtubules to kinetochores of sister chromatids, chromatids must remain paired after replication. This cohesion is mediated by the conserved cohesin complex comprised of SMC1, SMC3, SCC1, and either SA1 or SA2 in humans. Because defects in spindle assembly or sister chromatid cohesion can lead to aneuploidy in daughter cells, proper regulation of these processes is essential for fidelity in chromosome segregation. In an RNAi screen for regulators of spindle assembly, we identify the deubiquitinase USP37 as a regulator of mitotic progression, centrosome integrity, and chromosome alignment. USP37 associates with cohesin and contributes to sister chromatid resolution. Cohesion defects are rescued by expression of an RNAi-resistant USP37, but not the catalytically impaired USP37(C350A) mutant. Further, USP37 associates with WAPL, a negative regulator of cohesion necessary for cohesin release in prophase, in a manner dependent on USP37's second and third ubiquitin-interacting motifs. Depletion of USP37 reduces the stability of chromatin-associated WAPL and increases the fraction of WAPL that is more heavily ubiquitylated in mitosis. Consistently, overexpression of USP37(C350A) results in increased modification of WAPL, and addition of purified USP37(WT), but not USP37(C350A), to WAPL immunoprecipitates results in a reduction of ubiquitylated products. Taken together, our results ascribe a novel function for USP37 in mitotic progression and further suggest that USP37 positively regulates the stability of chromatin-associated WAPL to facilitate sister chromatid resolution.

A genetic map of the response to DNA damage in human cells

“…While USP37 has been previously linked to genome stability and processes influenced by DNA replication (Hernandez-Perez et al, 2016;Typas et al, 2016;Yeh et al, 2015), we speculate that USP37 may modulate the ubiquitylation state of replisome components, a finding that is supported by the observation that USP37 can be detected on nascent DNA by iPOND (Dungrawala et al, 2015) and that proximity proteomics placed USP37 in vicinity of core replisome components WDHD1 and MCM helicase subunits (Yeh et al, 2015).…”

RBMX is a component of the centromere noncoding RNP complex involved in cohesion regulation

“…Immunoprecipitation and Western blot analysis were carried out as described (Ideue et al., ). Fractionation of cell lysates to chromatin and soluble fractions was carried out as described (Yeh et al., ). Antibodies against GAPDH (sc‐25778 or sc‐47724), Aurora kinase B (sc‐14326), Wapl (sc‐98355), Pds5A (sc‐50782), and p53 (sc‐126) were purchased from Santa Cruz Biotechnology; antibody against phosphorylated Aurora (#2914) was purchased from Cell Signaling Technology; antibodies against RBMX (ab177347), Sororin (ab192237), and Smc3 (ab128919) were purchased from Abcam; and an antibody against Sgo1 (H00151648‐M01) was purchased from Abnova.…”

USP37 deubiquitinates Cdt1 and contributes to regulate DNA replication

“…Since its first description in 2011, USP37 function has been linked to a number of different proteins. These include important pro‐division regulators (Cyclin A, c‐Myc or 14‐3‐3γ) but also USP37 is able to regulate genomic stability by controlling DNA double strand break repair by homologous recombination or proper mitotic progression by controlling WAPL, a negative regulator of chromatin cohesion (Huang et al., 2011; Kim et al., 2015; Pan et al., 2014; Typas et al., 2015; Yeh et al., 2015).…”