Initiation of eukaryotic chromosome replication follows a spatiotemporal program. The current model suggests that replication origins compete for a limited pool of initiation factors. However, it remains to be answered how these limiting factors are preferentially recruited to early origins. Here, we report that Dbf4 is enriched at early origins through its interaction with forkhead transcription factors Fkh1 and Fkh2. This interaction is mediated by the Dbf4 C terminus and was successfully reconstituted in vitro. An interaction-defective mutant, , phenocopies alleles in terms of origin firing. Remarkably, genome-wide replication profiles reveal that the direct fusion of the DNA-binding domain (DBD) of Fkh1 to Dbf4 restores the Fkh-dependent origin firing but interferes specifically with the pericentromeric origin activation. Furthermore, Dbf4 interacts directly with Sld3 and promotes the recruitment of downstream limiting factors. These data suggest that Fkh1 targets Dbf4 to a subset of noncentromeric origins to promote early replication in a manner that is reminiscent of the recruitment of Dbf4 to pericentromeric origins by Ctf19.

Two sister chromatids must be held together by a cohesion process from their synthesis during S phase to segregation in anaphase. Despite its pivotal role in accurate chromosome segregation, how cohesion is established remains elusive. Here, we demonstrate that yeast Rtt101-Mms1, Cul4 family E3 ubiquitin ligases are stronger dosage suppressors of loss-of-function mutants than PCNA The essential cohesion reaction, Eco1-catalyzed Smc3 acetylation is reduced in the absence of Rtt101-Mms1. One of the adaptor subunits, Mms22, associates directly with Eco1. Point mutations (L61D/G63D) in Eco1 that abolish the interaction with Mms22 impair Smc3 acetylation. Importantly, an double mutant displays additive Smc3ac reduction. Moreover, Smc3 acetylation and cohesion defects also occur in the mutants of other replication-coupled nucleosome assembly (RCNA) factors upstream or downstream of Rtt101-Mms1, indicating unanticipated cross talk between histone modifications and cohesin acetylation. These data suggest that fork-associated Cul4-Ddb1 E3s, together with PCNA, coordinate chromatin reassembly and cohesion establishment on the newly replicated sister chromatids, which are crucial for maintaining genome and chromosome stability.

Background: Overactive TRPV4 mutants cause human diseases, such as skeletal dysplasias. Results: We identified C-terminal residues 838 -857 to be critical for folding and surface expression, thus contributing to the regulation of channel activity. Conclusion: Channels lacking the segment remain misfolded and are subjected to degradation via an ERAD-dependent pathway. Significance: Targeting the folding recognition domain presents attractive therapeutic potential for overactive TRPV4-mediated pathology.

Cohesin is a DNA-associated protein complex that forms a tripartite ring controlling sister chromatid cohesion, chromosome segregation and organization, DNA replication, and gene expression. Sister chromatid cohesion is established by the protein acetyltransferase Eco1, which acetylates two conserved lysine residues on the cohesin subunit Smc3 and thereby ensures correct chromatid separation in yeast (Saccharomyces cerevisiae) and other eukaryotes. However, the consequence of Eco1-catalyzed cohesin acetylation is unknown, and the exact nature of the cohesive state of chromatids remains controversial. Here, we show that self-interactions of the cohesin subunits Scc1/Rad21 and Scc3 occur in a DNA replication–coupled manner in both yeast and human cells. Using cross-linking MS-based and in vivo disulfide cross-linking analyses of purified cohesin, we show that a subpopulation of cohesin may exist as dimers. Importantly, upon temperature-sensitive and auxin-induced degron-mediated Eco1 depletion, the cohesin-cohesin interactions became significantly compromised, whereas deleting either the deacetylase Hos1 or the Eco1 antagonist Wpl1/Rad61 increased cohesin dimer levels by ∼20%. These results indicate that cohesin dimerizes in the S phase and monomerizes in mitosis, processes that are controlled by Eco1, Wpl1, and Hos1 in the sister chromatid cohesion-dissolution cycle. These findings suggest that cohesin dimerization is controlled by the cohesion cycle and support the notion that a double-ring cohesin model operates in sister chromatid cohesion.

ObjectiveTo analyze the relationship between 24‐h movement behaviors and adolescents' physical fitness, with sex difference and age disparity explored specifically.MethodsA total of 135 852 Chinese adolescents aged 13–22 years were included in this cross‐sectional study. Self‐reported 24‐h movement behavioral times, including moderate to vigorous physical activity (MVPA), recreational screen, and sleep, were identified as meeting guidelines based on Canadian recommendations. Physical fitness indicator (PFI) was calculated through sex‐ and age‐specific z scores of body mass index, forced vital capacity, 50 m dash, sit‐and‐reach, standing long jump, body muscle strength, and endurance running, and then classified as: low level (<20th), middle level (20th–80th), and high level (>80th). Mixed effect logistic regression was applied to analyze the association, and interaction terms were constructed to prove the sex and age disparities.ResultsOnly 12.4% of adolescents aged 13–22 years met all three recommendations. The number of meeting guidelines exhibited a typical dose–response relationship with high level PFI (OR = 1.22 [95% CI: 1.19–1.25]), and in detail, meeting MVPA + recreational screen (OR = 2.29 [95% CI: 2.09–2.51]) or MVPA‐only (OR = 2.16 [95% CI: 1.93–2.41]) guidelines were better associated with high‐level PFI. Besides, meeting MVPA‐only guideline was proved with stronger association with high‐level PFI for boys (p‐interaction = 0.005). The dose–response relationship in boys of the number of guidelines met with PFI was stronger in 19‐ to 22‐year‐olds (p‐interaction <0.001) and 16‐ to 18‐year‐olds (p‐interaction = 0.001) than that in 13‐ to 15‐year‐olds.ConclusionThe prevalence of meeting 24‐h movement behaviors guidelines among Chinese adolescents aged 13–22 years was relatively low. It was associated with adolescents' physical fitness, with meeting MVPA + recreational screen or MVPA‐only guidelines bringing greater benefits, and sex difference and age disparity existing.