Biology subjects

Lata, R.

Publications and source records attributed to Lata, R..

3 recordsLinked to original sources

bioRxiv2024

LEDGF interacts with the NID of MeCP2 and modulates MeCP2 condensates

Methyl-CpG-binding protein 2 (MeCP2) is a ubiquitously expressed nuclear protein that is involved in transcriptional regulation and chromatin remodeling. MeCP2 exists in two isoforms, MeCP2 E1 and MeCP2 E2, which share the same functional domains. Loss-of-function mutations in the MeCP2 gene are the main cause of Rett syndrome (RTT). Previous studies identified a direct interaction between MeCP2 and Lens Epithelium-derived Growth Factor (LEDGF), a transcriptional regulator that also exists in two isoforms, LEDGF/p75 and LEDGF/p52. Here, we further characterized the molecular and functional interaction between MeCP2 and LEDGF. The NID domain in MeCP2 is crucial for the binding to the PWWP-CR1 region of LEDGF. Introduction of R306C, a known RTT mutation in the NID of MeCP2, reduced the interaction with LEDGF. Our data reveal mutual inhibition of MeCP2 and LEDGF multimerization due to overlapping binding sites. In line with this observation, LEDGF depletion resulted in enlarged MeCP2 and heterochromatin condensates in NIH3T3 cells. Unraveling the molecular interaction and functional impact of the MeCP2-LEDGF interaction will increase our understanding of RTT pathogenesis.

molecular biology↗

bioRxiv2023

HDAC inhibitors rescue MeCP2T158M speckles in a high content screen

Rett syndrome (OMIM 312750) is a rare neurodevelopmental disorder caused by de novo mutations in the Methyl-CpG Binding Protein 2 (MeCP2) gene located on the X-Chromosome, typically affecting girls. Currently, available therapy for Rett Syndrome is only symptomatic. Rett syndrome symptoms first appear between 6 to 18 months of age, characterized by microcephaly and lack of motor coordination being the most prevalent. The disease continues to progress until adulthood when it reaches a stationary phase. More than 800 different mutations causing Rett syndrome have been described, yet the most common is T158M (9% prevalence), located in the Methyl-Binding domain (MBD) of MeCP2. Due to its importance for DNA binding through recognition of methylated CpG, mutations in the MBD have a significant impact on the stability and function of MeCP2. MeCP2 is a nuclear protein and accumulates in liquid-liquid phase condensates visualized as speckles in NIH3T3 by microscopy. We developed a high content phenotypic assay, detecting fluorescent MeCP2 speckles in NIH3T3 cells. The assay allows to identify small molecules that stabilize MeCP2-T158M and phenotypically rescue speckle formation. To validate the assay, a collection of 3572 drugs was screened, including FDA-approved drugs, compounds in clinical trials and biologically annotated tool compounds. 18 hits were identified showing at least 25% of rescue of speckles in the mutant cell line while not affecting wild-type MeCP2 speckles. Primary hits were confirmed in a dose response assay and in a thermal shift assay with recombinant MeCP2. One class of identified hits represents histone deacetylase inhibitors (HDACis) showing 25% speckle rescue of mutant MeCP2 without toxicity. This screening strategycan be expanded to additional compound libraries and support novel drug discovery.

cell biology↗

bioRxiv2020

Multiple loci linked to inversions are associated with eye size variation in species of the Drosophila virilis phylad

The size and shape of organs is tightly controlled to achieve optimal function. Natural morphological variations often represent functional adaptations to an ever-changing environment. For instance, variation in head morphology is pervasive in insects and the underlying molecular basis is starting to be revealed in the Drosophila genus for species of the melanogaster group. However, it remains unclear whether similar diversifications are governed by similar or different molecular mechanisms over longer timescales. To address this issue, we used species of the virilis phylad because they have been diverging from D. melanogaster for at least 40 million years. Our comprehensive morphological survey revealed remarkable differences in eye size and head shape among these species with D. novamexicana having the smallest eyes and southern D. americana populations having the largest eyes. We show that the genetic architecture underlying eye size variation is complex with multiple associated genetic variants located on most chromosomes. Our genome wide association study (GWAS) strongly suggests that some of the putative causative variants are associated with the presence of inversions. Indeed, northern populations of D. americana share derived inversions with D. novamexicana and they show smaller eyes compared to southern ones. Intriguingly, we observed a significant enrichment of genes involved in eye development on the 4th chromosome after intersecting chromosomal regions associated with phenotypic differences with those showing high differentiation among D. americana populations. We propose that variants associated with chromosomal inversions contribute to both intra- and inter-specific variation in eye size among species of the virilis phylad.

evolutionary biology↗