Unidirectional Arginine Transport in Reconstituted Plasma-Membrane Vesicles From Yeast Overexpressing CAN1

Eur J Biochem. 1993 Feb 1;211(3):683-8. doi: 10.1111/j.1432-1033.1993.tb17596.x.

Abstract

Amino acids are accumulated in Saccharomyces cerevisiae by strictly unidirectional influx systems. To see whether cellular compartmentation causes this unusual amino-acid-transport behaviour, arginine transport was studied in plasma-membrane vesicles. The arginine permease gene CAN1 was overexpressed in S. cerevisiae RH218a and in a permease-deficient mutant RS453 (can1). Reconstituted plasma-membrane vesicles from these transformants, energized by incorporated cytochrome-c oxidase, showed 3-4-fold increased rates of arginine uptake compared to vesicles from wild-type cells. The KT values were 32.5 microM in vesicles from wild-type and 28.6 microM in vesicles from transformed cells; the corresponding in vivo values were 17.5 microM and 11.4 microM, respectively. It could be demonstrated that unidirectional arginine transport and accumulation also exist in vesicles; thus, unidirectional influx is not related to cellular compartmentation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems*
  • Amino Acid Transport Systems, Basic
  • Arginine / metabolism*
  • Biological Transport
  • Cell Membrane / metabolism*
  • Gene Expression*
  • Kinetics
  • Liposomes / metabolism
  • Membrane Transport Proteins / genetics*
  • Membrane Transport Proteins / metabolism
  • Plasmids
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins
  • Transformation, Genetic

Substances

  • Amino Acid Transport Systems
  • Amino Acid Transport Systems, Basic
  • CAN1 protein, S cerevisiae
  • Liposomes
  • Membrane Transport Proteins
  • Saccharomyces cerevisiae Proteins
  • arginine permease
  • Arginine