Genetic and pharmacological modulation of lamin A farnesylation determines its function and turnover.

Hutchinson-Gilford Progeria syndrome (HGPS) is a severe premature ageing disorder caused by a 50 amino acid truncated (Δ50AA) and permanently farnesylated lamin A (LA) mutant called progerin. On a cellular level, progerin expression leads to heterochromatin loss, impaired nucleocytoplasmic transport, telomeric DNA damage and a permanent growth arrest called cellular senescence. Although the genetic basis for HGPS has been elucidated 20 years ago, the question whether the Δ50AA or the permanent farnesylation causes cellular defects has not been addressed.

Heterochromatin loss as a determinant of progerin-induced DNA damage in Hutchinson-Gilford Progeria.

Hutchinson-Gilford progeria is a premature aging syndrome caused by a truncated form of lamin A called progerin. Progerin expression results in a variety of cellular defects including heterochromatin loss, DNA damage, impaired proliferation and premature senescence. It remains unclear how these different progerin-induced phenotypes are temporally and mechanistically linked.

Inhibition of DNA damage response at telomeres improves the detrimental phenotypes of Hutchinson-Gilford Progeria Syndrome.

Hutchinson-Gilford progeria syndrome (HGPS) is a genetic disorder characterized by premature aging features. Cells from HGPS patients express progerin, a truncated form of Lamin A, which perturbs cellular homeostasis leading to nuclear shape alterations, genome instability, heterochromatin loss, telomere dysfunction and premature entry into cellular senescence. Recently, we reported that telomere dysfunction induces the transcription of telomeric non-coding RNAs (tncRNAs) which control the DNA damage response (DDR) at dysfunctional telomeres.

Premature aging syndromes: From patients to mechanism.

Aging is an inevitable consequence of human life resulting in a gradual deterioration of cell, tissue and organismal function and an increased risk to develop chronic ailments. Premature aging syndromes, also known as progeroid syndromes, recapitulate many clinical features of normal aging and offer a unique opportunity to elucidate fundamental mechanisms that contribute to human aging. Progeroid syndromes can be broadly classified into those caused by perturbations of the nuclear lamina, a meshwork of proteins located underneath the inner nuclear membrane (laminopathies); and a second group that is caused by mutations that directly impair DNA replication and repair.

2C-BioID: An Advanced Two Component BioID System for Precision Mapping of Protein Interactomes.

The modulation of protein-protein interactions (PPIs) is an essential regulatory activity defining diverse cell functions in development and disease. BioID is an unbiased proximity-dependent biotinylation method making use of a biotin-protein ligase fused to a protein of interest and has become an important tool for mapping of PPIs within cellular contexts. We devised an advanced method, 2C-BioID, in which the biotin-protein ligase is kept separate from the protein of interest, until the two are induced to associate by the addition of a dimerizing agent.

The RNA interactome of human telomerase RNA reveals a coding-independent role for a histone mRNA in telomere homeostasis.

Telomerase RNA (TR) provides the template for DNA repeat synthesis at telomeres and is essential for genome stability in continuously dividing cells. We mapped the RNA interactome of human TR (hTR) and identified a set of non-coding and coding hTR-interacting RNAs, including the histone 1C mRNA (). Disruption of the hTR- RNA association resulted in markedly increased telomere elongation without affecting telomerase enzymatic activity.

Loss of lamin B1 is a biomarker to quantify cellular senescence in photoaged skin.

Skin ageing is an inevitable consequence of life and accelerated by exposure to ultraviolet (UV) rays. Senescence is an irreversible growth arrest and senescent cells accumulate in ageing tissues, at sites of age-related pathologies and in pre-neoplastic lesions. Conventionally, senescent cells have been detected by senescence associated-β-galactosidase (SA-β-gal) staining, a procedure that requires enzymatic activity, which is lost in fixed tissue samples.

Progerin reduces LAP2α-telomere association in Hutchinson-Gilford progeria.

Hutchinson-Gilford progeria (HGPS) is a premature ageing syndrome caused by a mutation in LMNA, resulting in a truncated form of lamin A called progerin. Progerin triggers loss of the heterochromatic marker H3K27me3, and premature senescence, which is prevented by telomerase. However, the mechanism how progerin causes disease remains unclear.

Nuclear lamina remodelling and its implications for human disease.

The intermediate filament A- and B-type lamins are key architectural components of the nuclear lamina, a proteinaceous meshwork that lies underneath the inner nuclear membrane. In the past decade, many different monogenic human diseases have been linked to mutations in various components of the nuclear lamina. Mutations in LMNA (encoding lamin A and C) cause a variety of human diseases, collectively called laminopathies.

The contrasting roles of lamin B1 in cellular aging and human disease.

The nuclear lamina underlies the inner nuclear membrane and consists of a proteinaceous meshwork of intermediate filaments: the A- and B-type lamins. Mutations in LMNA (encoding lamin A and C) give rise to a variety of human diseases including muscular dystrophies, cardiomyopathies and the premature aging syndrome progeria (HGPS). Duplication of the LMNB1 locus, leading to elevated levels of lamin B1, causes adult-onset autosomal dominant leukodystrophy (ADLD), a rare genetic disease that leads to demyelination in the central nervous system (CNS).

Lamin B1 fluctuations have differential effects on cellular proliferation and senescence.

The nuclear lamina consists of A- and B-type lamins. Mutations in LMNA cause many human diseases, including progeria, a premature aging syndrome, whereas LMNB1 duplication causes adult-onset autosomal dominant leukodystrophy (ADLD). LMNB1 is reduced in cells from progeria patients, but the significance of this reduction is unclear.

The complete genome sequence of Clostridium difficile phage phiC2 and comparisons to phiCD119 and inducible prophages of CD630.

The complete genomic sequence of a previously characterized temperate phage of Clostridium difficile, C2, is reported. The genome is 56 538 bp and organized into 84 putative ORFs in six functional modules. The head and tail structural proteins showed similarities to that of C.

Hcc-2, a novel mammalian ER thioredoxin that is differentially expressed in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver. Thus there is great interest to identify novel HCC diagnostic markers for early detection of the disease and tumour specific associated proteins as potential therapeutic targets in the treatment of HCC. Currently, we are screening for early biomarkers as well as studying the development of HCC by identifying the differentially expressed proteins of HCC tissues during different stages of disease progression.

EST sequencing for gene discovery in Chinese hamster ovary cells.

Chinese hamster ovary (CHO) cells are one of the most important cell lines in biological research, and are the most widely used host for industrial production of recombinant therapeutic proteins. Despite their extensive applications, little sequence information is available for molecular based research. To facilitate gene discovery and genetic engineering, two cDNA libraries were constructed from three CHO cell lines grown under various conditions.