Biology subjects

Kadlec, J.

Publications and source records attributed to Kadlec, J..

5 recordsLinked to original sources

bioRxiv2023

Structural basis for competitive binding of productive and degradative co-transcriptional effectors to the nuclear cap-binding complex

The nuclear cap-binding complex (CBC) co-ordinates co-transcriptional maturation, transport, or degradation of nascent Pol II transcripts. CBC with its partner ARS2 form mutually exclusive complexes with diverse effectors that promote either productive or destructive outcomes. Combining Alphafold predictions with structural and biochemical validation, we show how effectors NCBP3, NELF-E, ARS2, PHAX and ZC3H18 form competing binary complexes with CBC and how PHAX, NCBP3, ZC3H18 and other effectors compete for binding to ARS2. In ternary CBCA complexes with either PHAX, NCBP3 or ZC3H18, ARS2 is responsible for the initial effector recruitment but inhibits their direct binding to the CBC. We show that in vivo ZC3H18 binding to both CBC and ARS2 is required for nuclear RNA degradation. We propose that recruitment of PHAX to CBC-ARS2 can lead, with appropriate cues, to competitive displacement of ARS2 and ZC3H18 from the CBC, thus promoting a productive rather than a degradative RNA fate.

biochemistry↗

bioRxiv2023

Putting cognitive tasks on trial: A measure of reliability convergence

The surge in interest in individual differences has coincided with the latest replication crisis centered around brain-wide association studies of brain-behavior correlations. Yet the reliability of the measures we use in cognitive neuroscience, a crucial component of this brain-behavior relationship, is often assumed but not directly tested. Here, we evaluate the reliability of different cognitive tasks on a large dataset of over 250 participants, who each completed a multi-day task battery. We show how reliability improves as a function of number of trials, and describe the convergence of the reliability curves for the different tasks, allowing us to score tasks according to their suitability for studies of individual differences. To improve the accessibility of these findings, we designed a simple web-based tool that implements this function to calculate the convergence factor and predict the expected reliability for any given number of trials and participants, even based on limited pilot data.

neuroscience↗

bioRxiv2023

Characterization of the REC114-MEI4-IHO1 complex regulating meiotic DNA double-strand break formation

Meiotic recombination is initiated by the formation of DNA double-strand breaks (DSBs), essential for fertility and genetic diversity. In the mouse, DSBs are formed by the catalytic TOPOVIL complex consisting of SPO11 and TOPOVIBL. To preserve genome integrity, the activity of the TOPOVIL complex is finely controlled by several meiotic factors including REC114, MEI4 and IHO1, but the underlying mechanism is poorly understood. Here, we report that mouse REC114 forms homodimers, that it associates with MEI4 as a 2:1 heterotrimer that further dimerizes, and that IHO1 forms coiled-coil based tetramers. Using AlphaFold2 modelling combined with biochemical characterization we uncovered the molecular details of these assemblies. Finally, we show that IHO1 directly interacts with the PH domain of REC114 by recognizing the same surface as TOPOVIBL and another meiotic factor ANKRD31. These results provide strong evidence for the existence of a ternary IHO1-REC114-MEI4 complex and show that REC114 is a potential regulatory platform mediating mutually exclusive interactions with several partners.

biochemistry↗

bioRxiv2022

Structural analysis of Red1 as a conserved scaffold of the RNA-targeting MTREC/PAXT complex

To eliminate specific or aberrant transcripts, eukaryotic cells use nuclear RNA-targeting complexes that deliver them to the exosome for degradation. S. pombe MTREC complex, and its human counterpart PAXT, are key players in this mechanism. Red1 and hZFC3H1 function as scaffolds of these respective complexes. Here, we present an NMR structure of a helix-turn-helix domain of Red1 in complex with the N-terminus of Iss10 and show this interaction is required for proper cellular growth and meiotic mRNA degradation. We also report a crystal structure of a Red1-Ars2 complex that explains the mutually exclusive interactions of hARS2 with various "ED/EGEI/L" motif-possessing RNA regulators such as hZFC3H1, hFLASH or hNCBP3. Finally, we show that both Red1 and hZFC3H1 homo-dimerize via their coiled-coil regions indicating that MTREC and PAXT likely function as dimers. Our results, combining structures of three Red1 binding interfaces with in vivo studies, provide mechanistic insights into conserved features of MTREC/PAXT architecture.

biochemistry↗

bioRxiv2021

TOPOVIBL-REC114 interaction regulates meiotic DNA double-strand breaks

Meiosis requires the formation of programmed DNA double strand breaks (DSBs), essential for fertility and for generating genetic diversity. DSBs are induced by the catalytic activity of the TOPOVIL complex formed by SPO11 and TOPOVIBL. To ensure genomic integrity, DNA cleavage activity is tightly regulated, and several accessory factors (REC114, MEI4, IHO1, and MEI1) are needed for DSB formation in mice. How and when these proteins act is not understood. Here, we show that REC114 is a direct partner of TOPOVIBL, and identified their conserved interacting domains by structural analysis. We then analysed the role of this interaction by monitoring meiotic DSBs in female and male mice carrying point mutations in TOPOVIBL that decrease or disrupt its binding to REC114. In these mutants, DSB activity was strongly reduced genome-wide in oocytes, and only in sub-telomeric regions in spermatocytes. In addition, in mutant spermatocytes, DSB activity was delayed in autosomes. These results provide evidence that REC114 is a key member of the TOPOVIL catalytic complex, and that the REC114/TOPOVIBL interaction ensures the efficiency and timing of DSB activity.

molecular biology↗