Does your lab coat fit to your assay?

An explanation for randomly occurring spikes on microplates in fluorescence-based assays employing shorter-wavelength readouts is presented. It is demonstrated that lint originating from standard (white cotton) lab coats is most likely to be responsible for such artifacts in assays applying wavelengths at 380 nm excitation and 450 nm emission. The fluorescence properties of this lint are discussed and compared with those of optical brighteners.

A novel principle for partial agonism of liver X receptor ligands. Competitive recruitment of activators and repressors.

Partial, selective activation of nuclear receptors is a central issue in molecular endocrinology but only partly understood. Using LXRs as an example, we show here that purely agonistic ligands can be clearly and quantitatively differentiated from partial agonists by the cofactor interactions they induce. Although a pure agonist induces a conformation that is incompatible with the binding of repressors, partial agonists such as GW3965 induce a state where the interaction not only with coactivators, but also corepressors is clearly enhanced over the unliganded state.

Automated yeast two-hybrid screening for nuclear receptor-interacting proteins.

High throughput analysis of protein-protein interactions is an important sector of hypothesis-generating research. Using an improved and automated version of the yeast two-hybrid system, we completed a large interaction screening project with a focus on nuclear receptors and their cofactors. A total of 425 independent yeast two-hybrid cDNA library screens resulted in 6425 potential interacting protein fragments involved in 1613 different interaction pairs.

Identification of farnesoid X receptor beta as a novel mammalian nuclear receptor sensing lanosterol.

Nuclear receptors are ligand-modulated transcription factors. On the basis of the completed human genome sequence, this family was thought to contain 48 functional members. However, by mining human and mouse genomic sequences, we identified FXRbeta as a novel family member.

Elucidation of an archaeal replication protein network to generate enhanced PCR enzymes.

Thermostable DNA polymerases are an important tool in molecular biology. To exploit the archaeal repertoire of proteins involved in DNA replication for use in PCR, we elucidated the network of proteins implicated in this process in Archaeoglobus fulgidus. To this end, we performed extensive yeast two-hybrid screens using putative archaeal replication factors as starting points.