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Faculty Sponsor

Dr. George S. Mourad


Department of Biology

University Affiliation

Indiana University – Purdue University Fort Wayne


The two genes PpNCS1A and PpNCS1B of the moss Physcomitrella patens are nucleobase transporters and putative members of the purine-related transporter (PRT) or nucleobase:cation symporter 1 (NCS1) family. Previously characterized members of this family include the uracil transporter (FUR 4) of Saccharomyces cerevisiae, the adenine-guanine-hypoxanthine-cytosine transporter (FCY2) of S. cerevisiae and the recently characterized adenine-guanine-uracil transporter (AtNCS1) of Arabidopsis thaliana. The two NCS1 genes of P. patens were cloned into yeast expression vectors and expressed in yeast strains lacking their own NCS1 genes. Transport profiles of the two P. patens NCS1 genes were discovered by radiolabeled nucleobase uptake and competition assays, and toxic analog growth studies. Interestingly, the two genes exhibit overlapping yet distinct solute specificities. PpNCS1A transports adenine, cytosine and uracil, but not guanine, while PpNCS1B transports adenine, cytosine and guanine, but not uracil. Future work will confirm the results presented here by yeast growth studies on media containing a sole nitrogen source, and kinetic parameters will be determined by radionucleobase homologous and/or heterologous competition assays.


Biology | Life Sciences

Two NCS1 transporters of the moss Physcomitrella patens share substrate specificities with other members of the NCS1 family but express novel phenotypes and distinct transport profiles

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