AtPTR1, a plasma membrane peptide transporter expressed during seed germination and in vascular tissue of Arabidopsis

Dietrich, Daniela; Hammes, Ulrich; Thor, Kathrin; Suter Grotemeyer, Marianne; Flückiger, Ricardo; Slusarenko, Alan J.; Ward, John M.; Rentsch, Doris (2004). AtPTR1, a plasma membrane peptide transporter expressed during seed germination and in vascular tissue of Arabidopsis. The Plant Journal, 40(4), pp. 488-499. Blackwell Science 10.1111/j.1365-313X.2004.02224.x

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For the efficient translocation of organic nitrogen, small peptides of two to three amino acids are posited as an important alternative to amino acids. A new transporter mediating the uptake of di- and tripeptides was isolated from Arabidopsis thaliana by heterologous complementation of a peptide transport-deficient Saccharomyces cerevisiae mutant. AtPTR1 mediated growth of S. cerevisiae cells on different di- and tripeptides and caused sensitivity to the phytotoxin phaseolotoxin. The spectrum of substrates recognized by AtPTR1 was determined in Xenopus laevis oocytes injected with AtPTR1 cRNA under voltage clamp conditions. AtPTR1 not only recognized a broad spectrum of di- and tripeptides, but also substrates lacking a peptide bond. However, amino acids, omega-amino fatty acids or peptides with more than three amino acid residues did not interact with AtPTR1. At pH 5.5 AtPTR1 had an apparent lower affinity (K-0.5 = 416 mum) for Ala-Asp compared with Ala-Ala (K-0.5 = 54 mum) and Ala-Lys (K-0.5 = 112 mum). Transient expression of AtPTR1/GFP fusion proteins in tobacco protoplasts showed that AtPTR1 is localized at the plasma membrane. In addition, transgenic plants expressing the beta-glucuronidase (uidA) gene under control of the AtPTR1 promoter demonstrated expression in the vascular tissue throughout the plant, indicative of a role in long-distance transport of di- and tripeptides.

Item Type:	Journal Article (Original Article)
Division/Institute:	08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Molecular Plant Physiology 08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)
UniBE Contributor:	Thor, Kathrin, Suter, Marianne, Rentsch, Doris
Subjects:	500 Science > 580 Plants (Botany)
ISSN:	0960-7412
Publisher:	Blackwell Science
Language:	English
Submitter:	Peter Alfred von Ballmoos-Haas
Date Deposited:	06 Jun 2014 13:48
Last Modified:	05 Dec 2022 14:34
Publisher DOI:	10.1111/j.1365-313X.2004.02224.x
Uncontrolled Keywords:	transport, peptides, Arabidopsis, nitrogen reallocation
URI:	https://boris.unibe.ch/id/eprint/53319