High impact information on RSB1

• Together, these data indicate Pdr3p activation of RSB1 transcription is an important feature of the retrograde response allowing normal detoxification of an endogenous sphingolipid precursor [1].
• Two glycosylation sites are present in the Rsb1p and both are required for normal LCB resistance [1].
• Here we employ a full-length form of Rsb1p and find that this protein is localized to the plasma membrane and is modified by N-linked glycosylation [1].
• This membrane protein has been designated Rsb1p and has previously been shown to act as a LCB transporter protein and to be a component of the endoplasmic reticulum [1].
• We found that the expression of Rsb1p was increased in the pdr5 mutants [2].

Biological context of RSB1

• Mutational analysis of the RSB1 promoter revealed that two Pdr3p binding sites are present and both of these are required for normal retrograde induction of transcription [1].
• Here, we identified a novel yeast gene, RSB1 (resistance to sphingoid long-chain base), by screening a multicopy suppressor of the LCB-sensitive phenotype of the LCBP lyase mutant [3].
• Substrate specificity analysis of Rsb1p demonstrated that it is active on LCBs but not on LCBPs or other hydrophobic compounds [3].

Associations of RSB1 with chemical compounds

• Identification and characterization of a Saccharomyces cerevisiae gene, RSB1, involved in sphingoid long-chain base release [3].
• We demonstrated that cells overproducing Rsb1p showed a decrease in accumulation of exogenously added sphingosine and dihydrosphingosine because of their increased release [3].
• Genetic analysis revealed that the PHS-resistant phenotypes exhibited by the pdr5 mutants were dependent on Rsb1p, a putative LCB-specific transporter/translocase [2].

Regulatory relationships of RSB1

• We also demonstrated that expression of RSB1 is under the control of the transcriptional factor Pdr1p [2].

References