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Christian Conrad

Publications and source records attributed to Christian Conrad.

4 recordsLinked to original sources

Automatic identification of subcellular phenotypes on human cell arrays.

Light microscopic analysis of cell morphology provides a high-content readout of cell function and protein localization. Cell arrays and microwell transfection assays on cultured cells have made cell phenotype analysis accessible to high-throughput experiments. Both the localization of each protein in the proteome and the effect of RNAi knock-down of individual genes on cell morphology can be assayed by manual inspection of microscopic images. However, the use of morphological readouts for functional genomics requires fast and automatic identification of complex cellular phenotypes. Here, we present a fully automated platform for high-throughput cell phenotype screening combining human live cell arrays, screening microscopy, and machine-learning-based classification methods. Efficiency of this platform is demonstrated by classification of eleven subcellular patterns marked by GFP-tagged proteins. Our classification method can be adapted to virtually any microscopic assay based on cell morphology, opening a wide range of applications including large-scale RNAi screening in human cells.

Artifacts↗

One functional subunit is sufficient for catalytic activity and substrate specificity of Escherichia coli endoribonuclease III artificial heterodimers.

To study the intersubunit communication required for the activity of the normally homodimeric enzyme endoribonuclease III of Escherichia coli we have constructed and analysed an artificial heterodimer. This heterodimer is composed of one wild-type and one catalytically inactive subunit. The inactive subunit has one amino acid exchanged (E117K, rnc70 mutant) which abolishes cleavage activity but still allows substrate binding of a rnc70-homodimer. Our results show that one functional active site is sufficient for cleavage activity of the heterodimer.

Base Sequence↗

Ribonuclease III: new sense from nuisance.

RNases play an important role in the processing of precursor RNAs, creating the mature, functional RNAs. The ribonuclease III family currently is one of the most interesting families of endoribonucleases. Surprisingly, RNase III is involved in the maturation of almost every class of prokaryotic and eukaryotic RNA. We present an overview of the various substrates and their processing. RNase III contains one of the most prominent protein domains used in RNA-protein recognition, the double-stranded RNA binding domain (dsRBD). Progress in the understanding of this domain is summarized. Furthermore, RNase III only recently emerged as a key player in the new exciting biological field of RNA silencing, or RNA interference. The eukaryotic RNase III homologues which are likely involved in this process are compared with the other members of the RNase III family.

Animals↗