Stm1 is a vacuolar PQ-loop protein involved in the transport of basic amino acids in Schizosaccharomyces pombe

• Published in: Biochimica et biophysica acta. Biomembranes Vol. 1863; no. 2; p. 183507
• Main Authors: Kawano-Kawada, Miyuki, Ueda, Taisuke, Mori, Hikari, Ichimura, Haruka, Takegawa, Kaoru, Sekito, Takayuki
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2021
• Subjects: Arginine - genetics; Arginine - metabolism; Basic amino acids; Biological Transport, Active - physiology; Genetic Complementation Test; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Intracellular Membranes - metabolism; Lysine - genetics; Lysine - metabolism; Membrane Proteins - genetics; Membrane Proteins - metabolism; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; PQ-loop; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Schizosaccharomyces - genetics; Schizosaccharomyces - metabolism; Schizosaccharomyces pombe Proteins - genetics; Schizosaccharomyces pombe Proteins - metabolism; Transport; Vacuolar membrane protein; Vacuoles - genetics; Vacuoles - metabolism; SD; ORF; BF; PQ-loop; GPCR; LCT; Vacuolar membrane protein; Transport; TOG; Basic amino acids
• ISSN: 0005-2736; 1879-2642
• DOI: 10.1016/j.bbamem.2020.183507

The stm1+ (SPAC17C9.10) gene of Schizosaccharomyces pombe is closely related to genes encoding vacuolar PQ-loop proteins, Ypq1, Ypq2, and Ypq3, of Saccharomyces cerevisiae. When stm1+ fused with GFP was expressed in fission or budding yeast, Stm1-GFP localized at the vacuolar membrane. Isolated vacuolar membrane vesicles from S. cerevisiae cells overexpressing stm1+ exhibited stm1+-dependent arginine and lysine uptake activity. Exchange activity of arginine and histidine/arginine, as observed for Ypq2 of S. cerevisiae, was also detected in the vesicles expressing stm1+. The expression levels of stm1+ in S. pombe cells significantly affected the vacuolar contents of lysine, histidine, and arginine. These results suggest that Stm1 is a vacuolar PQ-loop protein involved in the transport of basic amino acids across the vacuolar membrane. Transport of amino acids across the vacuolar membrane of fission yeast, Schizosaccharomyces pombe. [Display omitted] •Stm1 of the fission yeast Schizosaccharomyces pombe is a vacuolar PQ-loop protein.•Transport activities of basic amino acids were detected with isolated vacuolar membrane vesicles expressing stm1+.•Stm1 is required for the amino acid compartmentalization in vacuoles of fission yeast.