The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

A nonconserved Ala401 in the yeast Rsp5 ubiquitin ligase is involved in degradation of Gap1 permease and stress-induced abnormal proteins.

A toxic l-proline analogue, l-azetidine-2-carboxylic acid (AZC), causes misfolding of the proteins into which it is incorporated competitively with l-proline, thereby inhibiting the growth of the cells. AZC enters budding yeast Saccharomyces cerevisiae cells primarily through the general amino acid permease Gap1, not through the proline-specific permease Put4. We isolated an AZC-hypersensitive mutant that cannot grow even at low concentrations of AZC because of the accumulation of intracellular AZC. By screening through a yeast genomic library, the mutant was found to carry an allele of RSP5 encoding an E3 ubiquitin ligase. A single amino acid change replacing Ala (GCA) at position 401 with Glu (GAA) showed that Ala-401 in the third WW domain (a protein interaction module) is not conserved in the domain. The addition of NH4+ to yeast cells growing on l-proline induced rapid ubiquitination, endocytosis, and vacuolar degradation of the plasma membrane protein Gap1. However, immunoblot and permease assays indicated that Gap1 in the rsp5 mutant remained stable and active on the plasma membrane probably with no ubiquitination, leading to AZC accumulation and hypersensitivity. The rsp5 mutants also showed hypersensitivity to various stresses (toxic amino acid analogues, high temperature in a rich medium, and oxidative treatments) and defects in spore growth. These results suggest that Rsp5 is involved in selective degradation of abnormal proteins and specific proteins for spore growth, in addition to nitrogen-regulated degradation of Gap1. Furthermore, Ala-401 of Rsp5 was considered to have an important role in the ubiquitination of targeted proteins.[1]


  1. A nonconserved Ala401 in the yeast Rsp5 ubiquitin ligase is involved in degradation of Gap1 permease and stress-induced abnormal proteins. Hoshikawa, C., Shichiri, M., Nakamori, S., Takagi, H. Proc. Natl. Acad. Sci. U.S.A. (2003) [Pubmed]
WikiGenes - Universities