Biology subjects

Veverka, P.

Publications and source records attributed to Veverka, P..

3 recordsLinked to original sources

bioRxiv2023

Structural insights into inherited anemia CDA-I: disease-associated mutations disrupt CDIN1-Codanin1 complex

Congenital dyserythropoietic anemia type I (CDA-I) is a rare hereditary disease marked by ineffective erythropoiesis, a characteristic spongy heterochromatin structure in erythroblasts, and mutations in the genes CDAN1 and CDIN1, which encode the proteins Codanin1 and CDIN1. Codanin1 regulates histone shuttling via the chaperone ASF1, yet the role of CDIN1 in CDA-I pathology remains unclear. Notably, CDIN1 is known to interact directly with the C-terminus of Codanin1. Although mutations in both genes are critical to the disease phenotype, their molecular-level effects have not been fully elucidated. Here, we present a comprehensive structural and functional analysis of the CDIN1-Codanin1 C-terminus complex. Using complementary biophysical techniques, we show that CDIN1 and Codanin1 C-terminus form a high-affinity heterodimeric complex with equimolar stoichiometry. We further delineate the essential interacting regions of CDIN1 and Codanin1. We demonstrate that CDA-I-associated mutations in either protein disrupt CDIN1-Codanin1 interaction, suggesting a potential molecular mechanism underlying the disease. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=116 SRC="FIGDIR/small/542057v3_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1ca4364org.highwire.dtl.DTLVardef@e74ccorg.highwire.dtl.DTLVardef@1160f92org.highwire.dtl.DTLVardef@158536b_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2022

Electron microscopy reveals toroidal shape of master neuronal cell differentiator REST - RE1-Silencing Transcription factor

The RE1-Silencing Transcription factor (REST) is essential for neuronal differentiation. Here, we report the first 18.5-angstrom electron microscopy structure of human REST. The refined electron map suggests that REST forms a torus that can accommodate DNA double-helix in the central hole. Additionally, we quantitatively described REST binding to the canonical DNA sequence of the neuron-restrictive silencer element. We developed protocols for the expression and purification of full-length REST and the shortened variant REST-N62 produced by alternative splicing. We tested the mutual interaction of full-length REST and the splicing variant REST-N62. Revealed structure-function relationships of master neuronal repressor REST will allow finding new biological ways of prevention and treatment of neurodegenerative disorders and diseases.

biochemistry↗

bioRxiv2018

Human telomere repeat binding factor TRF1 replaces TRF2 bound to shelterin core hub TIN2 when TPP1 is absent

Human telomeric repeat binding factors TRF1, TRF2 along with TIN2 form a core of shelterin complex that protects chromosome ends against unwanted end-joining and DNA repair. We applied a single-molecule approach to assess TRF1-TIN2-TRF2 complex formation in solution at physiological conditions. Fluorescence Cross-Correlation Spectroscopy (FCCS) was used to describe the complex formation by analyzing how coincident fluctuations of differently labeled TRF1 and TRF2 correlate when they move together through the confocal volume of the microscope. We observed, at the single-molecule level, that TRF1 effectively substituted TRF2 on TIN2. We assessed the effect of another telomeric factor TPP1 that recruits telomerase to telomeres. We found that TPP1 upon binding to TIN2 induces allosteric changes that expand TIN2 binding capacity, such that TIN2 can accommodate both TRF1 and TRF2 simultaneously. We suggest a molecular model that explains why TPP1 is essential for the stable formation of TRF1-TIN2-TRF2 core complex.

biochemistry↗