Expansion mutations in polyalanine stretches are associated with a growing number of diseases sharing a high degree of genotypic and phenotypic commonality. These similarities prompted us to query the normal function of physiological polyalanine stretches and to investigate whether a common molecular mechanism is involved in these diseases. Here, we show that UBA6, an E1 ubiquitin-activating enzyme, recognizes a polyalanine stretch within its cognate E2 ubiquitin-conjugating enzyme USE1.
View Article and Find Full Text PDFAutism Spectrum Disorder (ASD) is characterized mainly by social and sensory-motor abnormal and repetitive behavior patterns. Over hundreds of genes and thousands of genetic variants were reported to be highly penetrant and causative of ASD. Many of these mutations cause comorbidities such as epilepsy and intellectual disabilities (ID).
View Article and Find Full Text PDFDilated cardiomyopathy (DCM) is a primary myocardial disease, leading to heart failure and excessive risk of sudden cardiac death with rather poorly understood pathophysiology. In 2015, Parvari's group identified a recessive mutation in the autophagy regulator, PLEKHM2 gene, in a family with severe recessive DCM and left ventricular non-compaction (LVNC). Fibroblasts isolated from these patients exhibited abnormal subcellular distribution of endosomes, Golgi apparatus, lysosomes and had impaired autophagy flux.
View Article and Find Full Text PDFPleckstrin Homology And RUN Domain Containing M2 (PLEKHM2) [delAG] mutation causes dilated cardiomyopathy with left ventricular non-compaction (DCM-LVNC), resulting in a premature death of PLEKHM2[delAG] individuals due to heart failure. PLEKHM2 is a factor involved in autophagy, a master regulator of cellular homeostasis, decomposing pathogens, proteins and other cellular components. Autophagy is mainly carried out by the lysosome, containing degradation enzymes, and by the autophagosome, which engulfs substances marked for decomposition.
View Article and Find Full Text PDFPhelan-McDermid syndrome (PMS) is a rare genetic condition that causes global developmental disability, delayed or absent speech, and an autism spectrum disorder. The loss of function of one copy of SHANK3, which codes for a scaffolding protein found in the postsynaptic density of synapses, has been identified as the main cause of PMS. We report the generation and characterization of two induced pluripotent stem cell (iPSC) lines derived from one patient with a SHANK3 mutation and the patient's mother as a control.
View Article and Find Full Text PDFObstructive sleep apnea syndrome (OSAS) patients suffer from cardiovascular morbidity, which is the leading cause of death in this disease. Based on our previous work with transformed cell lines and primary rat cardiomyocytes, we determined that upon incubation with sera from pediatric OSAS patients, the cell's morphology changes, NF-κB pathway is activated, and their beating rate and viability decreases. These results suggest an important link between OSAS, systemic inflammatory signals and end-organ cardiovascular diseases.
View Article and Find Full Text PDFFamilial Dysautonomia (FD) is an autosomal recessive congenital neuropathy affecting the development and function of the peripheral nervous system. FD causing gene is IKBKAP, encoding IkappaB kinase complex-associated protein also named elongator complex like protein 1 (IKAP/ELP1). The most common mutation (IVS20 + 6 T > C) causes an exon 20 skipping, leading to a truncated protein.
View Article and Find Full Text PDFAutophagy serves as a master regulator of cellular homeostasis. Hence, expectedly autophagic dysfunction has been documented in many diseases such as cancer, neurodegeneration and cardiovascular disorders. A novel homozygous mutation in PLEKHM2 gene (mPLEKHM2) resulted in dilated cardiomyopathy with left ventricular noncompaction (DCM-LVNC), probably as result of impaired autophagy due to disruption of lysosomal movement assisted by PLEKHM2.
View Article and Find Full Text PDFThe GLUN2D subunit of the N-methylD-aspartate receptor (NMDAR) is encoded by the GRIN2D gene. Mutations in GRIN2D have been associated with neurodevelopmental and epileptic encephalopathies. Access to patient samples harboring mutations in GRIN2D can contribute to understanding the role of NMDAR in neuronal development and function.
View Article and Find Full Text PDFp450 oxidoreductase (POR) cytochromes are enzymes involved in the metabolism of steroids and sex hormones, in which POR acts as an electron donor. Inactivating mutations in the POR gene cause diverse deficiencies. Access to patient samples carrying these POR mutations can contribute to the understanding of metabolic and developmental processes.
View Article and Find Full Text PDFCongenital central hypoventilation syndrome (CCHS) is a rare life-threatening condition affecting the autonomic nervous system that usually presents shortly after birth as hypoventilation or central apnea during sleep. In the majority of cases, heterozygous polyalanine expansion mutations within the third exon of the paired-like homeobox 2B (PHOX2B) gene underlie CCHS. Here, we report the generation of two induced pluripotent stem cell (iPSC) lines from two identical twins with a heterozygous PHOX2B expansion mutation (+5 alanine residues).
View Article and Find Full Text PDFProliferating cell nuclear antigen (PCNA) is considered as a hub protein and is a key regulator of DNA replication, repair, cell cycle control, and apoptosis. PCNA is overexpressed in many cancer types, and PCNA overexpression is correlated with cancer virulence. Membrane-associated PCNA is a ligand for the NKp44 (NCR2) innate immune receptor.
View Article and Find Full Text PDFRSRC1, whose polymorphism is associated with altered brain function in schizophrenia, is a member of the serine and arginine rich-related protein family. Through homozygosity mapping and whole exome sequencing we show that RSRC1 mutation causes an autosomal recessive syndrome of intellectual disability, aberrant behaviour, hypotonia and mild facial dysmorphism with normal brain MRI. Further, we show that RSRC1 is ubiquitously expressed, and that the RSRC1 mutation triggers nonsense-mediated mRNA decay of the RSRC1 transcript in patients' fibroblasts.
View Article and Find Full Text PDFIn this study, we found that the measles virus (MV) can infect human-induced pluripotent stem cells (hiPSCs). Wild-type MV strains generally use human signaling lymphocyte activation molecule (SLAM; CD150) as a cellular receptor, while vaccine strains such as the Edmonston strain can use both CD150 and CD46 as receptors. It is not yet known how early in the embryonal differentiation stages these receptors are expressed.
View Article and Find Full Text PDFα-Hederin, a natural triterpene saponin and its derivative kalopanaxsaponin I (ksI) exhibit cytotoxicity against various cancer cell lines and IN VIVO tumors. We studied the genetic variants contributing to the activity of these two anticancer compounds. Cell lines derived from 30 trios of European descent (Centre d'Etude du Polymorphisme Human, CEPH; CEU) and 30 trios of African descent (Yoruban, YRI) were used.
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