SAF-A forms a complex with BRG1 and both components are required for RNA polymerase II mediated transcription.

Background: Scaffold attachment factor A (SAF-A) participates in the regulation of gene expression by organizing chromatin into transcriptionally active domains and by interacting directly with RNA polymerase II.

Methodology: Here we use co-localization, co-immunoprecipitation (co-IP) and in situ proximity ligation assay (PLA) to identify Brahma Related Gene 1 (BRG1), the ATP-driven motor of the human SWI-SNF chromatin remodeling complex, as another SAF-A interaction partner in mouse embryonic stem (mES) cells. We also employ RNA interference to investigate functional aspects of the SAF-A/BRG1 interaction.

Post-nephrectomy development of renal function in living kidney donors: a cross-sectional retrospective study.

Background: Increasing numbers of living donor kidney transplantations calls for better knowledge about long-term donor outcomes and risks.

Methods: To explore long-term kidney donor outcomes and risks, we conducted a cross sectional retrospective study. To this end, we analysed renal function using measured glomerular filtration rate (mGFR) and estimated glomerular filtration rate (eGFR) as well as microalbuminuria, blood pressure (BP), body mass index, haemoglobin, albumin and parathyroid hormone in kidney donors nephrectomized between 1965 and 2005.

SAF-A has a role in transcriptional regulation of Oct4 in ES cells through promoter binding.

Methodologies to reprogram somatic cells into patient-specific pluripotent cells, which could potentially be used in personalized drug discovery and cell replacement therapies, are currently under development. Oct4 activation is essential for successful reprogramming and pluripotency of embryonic stem (ES) cells, albeit molecular details of Oct4 activation are not completely understood. Here we report that endogenous SAF-A is involved in regulation of Oct4 expression, binds the Oct4 proximal promoter in ES cells, and dissociates from the promoter upon early differentiation induced by LIF withdrawal.

Phosphorylated nucleolin interacts with translationally controlled tumor protein during mitosis and with Oct4 during interphase in ES cells.

Background: Reprogramming of somatic cells for derivation of either embryonic stem (ES) cells, by somatic cell nuclear transfer (SCNT), or ES-like cells, by induced pluripotent stem (iPS) cell procedure, provides potential routes toward non-immunogenic cell replacement therapies. Nucleolar proteins serve as markers for activation of embryonic genes, whose expression is crucial for successful reprogramming. Although Nucleolin (Ncl) is one of the most abundant nucleolar proteins, its interaction partners in ES cells have remained unidentified.

G-quadruplex structures in RNA stimulate mitochondrial transcription termination and primer formation.

The human mitochondrial transcription machinery generates the primers required for initiation of leading-strand DNA replication. According to one model, the 3' end of the primer is defined by transcription termination at conserved sequence block II (CSB II) in the mitochondrial DNA control region. We here demonstrate that this site-specific termination event is caused by G-quadruplex structures formed in nascent RNA upon transcription of CSB II.

Translationally controlled tumor protein interacts with nucleophosmin during mitosis in ES cells.

Somatic cell nuclear transfers and the generation of induced pluripotent stem cells provide potential routes towards non-immunogenic cell replacement therapies. Translationally controlled tumor protein (Tpt1) was recently suggested to regulate cellular pluripotency. Here we explore functions of Tpt1 in mouse embryonic stem (ES) cells.

Developmental studies of Xenopus shelterin complexes: the message to reset telomere length is already present in the egg.

The 6-protein complex shelterin protects the telomeres of human chromosomes. The recent discovery that telomeres are important for epigenetic gene regulation and vertebrate embryonic development calls for the establishment of model organisms to study shelterin and telomere function under normal developmental conditions. Here, we report the sequences of the shelterin-encoding genes in Xenopus laevis and its close relation Xenopus tropicalis.

Telomerase recruitment by the telomere end binding protein-beta facilitates G-quadruplex DNA unfolding in ciliates.

The telomeric G-overhangs of the ciliate Stylonychia lemnae fold into a G-quadruplex DNA structure in vivo. Telomeric G-quadruplex formation requires the presence of two telomere end binding proteins, TEBPalpha and TEBPbeta, and is regulated in a cell-cycle dependent manner. Unfolding of this structure in S phase is dependent on the phosphorylation of TEBPbeta.

Identification and characterization of an essential telomeric repeat binding factor in fission yeast.

Whereas mammalian cells harbor two double strand telomeric repeat binding factors, TRF1 and TRF2, the fission yeast Schizosaccharomyces pombe has been thought to harbor solely the TRF1/TRF2 ortholog Taz1p to perform comparable functions. Here we report the identification of telomeric repeat binding factor 1 (Tbf1), a second TRF1/TRF2 ortholog in S. pombe.

Telomere end-binding proteins control the formation of G-quadruplex DNA structures in vivo.

Telomere end-binding proteins (TEBPs) bind to the guanine-rich overhang (G-overhang) of telomeres. Although the DNA binding properties of TEBPs have been investigated in vitro, little is known about their functions in vivo. Here we use RNA interference to explore in vivo functions of two ciliate TEBPs, TEBPalpha and TEBPbeta.

A substrate for telomerase.

Recent data indicates that controlled in vivo synthesis of telomeric DNA is a 'ménage à trois', in which sister chromatid termini paired by telomere end-binding protein constitute a core substrate for a telomerase dimer. Such an arrangement could serve to fine tune synthesis of telomeric DNA and might ensure similar telomerase processivity for paired sister chromatid termini, possibly to secure the maintenance of individual telomere lengths in daughter cells. It also suggests that the bona fide end-capping protein, which is likely to regulate telomerase by restricting access to chromosome termini, has escaped detection in man.

Telomere architecture.

Telomeres are protein-DNA complexes that cap chromosome ends and protect them from being recognized and processed as DNA breaks. Loss of capping function results in genetic instability and loss of cellular viability. The emerging view is that maintenance of an appropriate telomere structure is essential for function.

c-myc Suppression in Burkitt's lymphoma cells.

The purpose of the study was to elucidate how DNA tetraplex (also referred to as G-quadruplex)-forming oligonucleotides mediate suppression of the human c-myc gene at the level of transcription initiation. A 22-base-long oligonucleotide, which is rich in guanines and folds into an intrastrand DNA tetraplex under physiological conditions, was administered to a Burkitt's lymphoma cell line overexpressing a (8:14) translocated c-myc allele. Administration of the oligonucleotide at nanomolar concentrations to the surrounding medium resulted in efficient cellular uptake, and was accompanied by a substantial concentration- and conformation-dependent decrease in growth rate.