Biomedical subjects

Robin Haw

Publications and source records attributed to Robin Haw.

4 recordsLinked to original sources

PubMed2006

Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.

Identification of protein-protein interactions often provides insight into protein function, and many cellular processes are performed by stable protein complexes. We used tandem affinity purification to process 4,562 different tagged proteins of the yeast Saccharomyces cerevisiae. Each preparation was analysed by both matrix-assisted laser desorption/ionization-time of flight mass spectrometry and liquid chromatography tandem mass spectrometry to increase coverage and accuracy. Machine learning was used to integrate the mass spectrometry scores and assign probabilities to the protein-protein interactions. Among 4,087 different proteins identified with high confidence by mass spectrometry from 2,357 successful purifications, our core data set (median precision of 0.69) comprises 7,123 protein-protein interactions involving 2,708 proteins. A Markov clustering algorithm organized these interactions into 547 protein complexes averaging 4.9 subunits per complex, about half of them absent from the MIPS database, as well as 429 additional interactions between pairs of complexes. The data (all of which are available online) will help future studies on individual proteins as well as functional genomics and systems biology.

Biological Evolution↗

PubMed2004

Role of the N-terminal region of Rap1p in the transcriptional activation of glycolytic genes in Saccharomyces cerevisiae.

In the yeast two-hybrid system, the N-terminal region of Rap1p was shown to interact with Gcr1p and Gcr2p. Disruption of gcr1 and/or gcr2 in the two-hybrid reporter strain demonstrated that the interaction with Gcr1p does not require Gcr2p, whereas the interaction with Gcr2p is mediated through Gcr1p. Deletion of the N-terminal region of Rap1p alone did not show a growth phenotype, but a growth defect was observed when this mutation was combined with a gcr2 deletion. The poor growth of the gcr1 null mutant was not affected further by the N-terminal deletion of Rap1p, but the growth of gcr1 strains with mutations in the DNA binding region of Gcr1p was affected by the removal of the N-terminal region of Rap1p. These results suggest that one function of the N-terminal region of Rap1p, presumably the BRCT domain, is to facilitate the binding of Gcr1p to the promoter by a protein-protein interaction.

Blotting, Western↗

PubMed2004

High-definition macromolecular composition of yeast RNA-processing complexes.

A remarkably large collection of evolutionarily conserved proteins has been implicated in processing of noncoding RNAs and biogenesis of ribonucleoproteins. To better define the physical and functional relationships among these proteins and their cognate RNAs, we performed 165 highly stringent affinity purifications of known or predicted RNA-related proteins from Saccharomyces cerevisiae. We systematically identified and estimated the relative abundance of stably associated polypeptides and RNA species using a combination of gel densitometry, protein mass spectrometry, and oligonucleotide microarray hybridization. Ninety-two discrete proteins or protein complexes were identified comprising 489 different polypeptides, many associated with one or more specific RNA molecules. Some of the pre-rRNA-processing complexes that were obtained are discrete sub-complexes of those previously described. Among these, we identified the IPI complex required for proper processing of the ITS2 region of the ribosomal RNA primary transcript. This study provides a high-resolution overview of the modular topology of noncoding RNA-processing machinery.

Amino Acid Sequence↗

PubMed2004

Isolation and characterization of Candida albicans homologue of RAP1, a repressor and activator protein gene in Saccharomyces cerevisiae.

To study the function of RAP1, a Candida albicans gene (CaRAP1) that shows sequence similarity to RAP1 of Saccharomyces cerevisiae was isolated by colony hybridization. DNA sequencing predicted an open reading frame of 429 amino acids with an overall identity of 24% to the ScRap1p. The DNA binding domain (DBD) was highly conserved, and EMSA using a GST-CaRap1p fusion protein confirmed its binding ability to the RPG-box of S. cerevisiae ENO1. In contrast, the N-terminus was less conserved and a moderate homology was observed in the BRCT domain. Interestingly, CaRap1p did not contain the C-terminal activation/repression region of ScRap1p.

Amino Acid Sequence↗