Regulation of yeast nutrient permease endocytosis by ATP-binding cassette transporters and a seven-transmembrane protein, RSB1.
Ceramide is produced by the condensation of a long chain base with a very long chain fatty acid. In Saccharomyces cerevisiae, one of the two major long chain bases is called phytosphingosine (PHS). PHS has been shown to cause toxicity in tryptophan auxotrophic strains of yeast because this bioactive ceramide precursor causes diversion of the high affinity tryptophan permease Tat2 to the vacuole rather than the plasma membrane. Loss of the integral membrane protein Rsb1 increased PHS sensitivity, which was suggested to be due to this protein acting as an ATP-dependent long chain base efflux protein. More recent experiments demonstrated that loss of the genes encoding the ATP-binding cassette transporter proteins Pdr5 and Yor1 elevated PHS tolerance. This increased resistance was suggested to be due to increased expression of RSB1. Here, we provide an alternative view of PHS resistance influenced by Rsb1 and Pdr5/Yor1. Rsb1 has a seven-transmembrane domain topology more consistent with that of a regulatory protein like a G-protein-coupled receptor rather than a transporter. Importantly, an rsb1Δ cell does not exhibit higher internal levels of PHS compared with isogenic wild-type cells. However, tryptophan transport is increased in pdr5Δ yor1 strains and reduced in rsb1Δ cells. Localization and vacuolar degradation of Tat2 are affected in these genetic backgrounds. Finally, internalization of FM4-64 dye suggests that loss of Pdr5 and Yor1 slows normal endocytic rates. Together, these data argue that Rsb1, Pdr5, and Yor1 regulate the endocytosis of Tat2 and likely other membrane transporter proteins.
Johnson
Soraya S
SS
Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.
Hanson
Pamela K
PK
Manoharlal
Raman
R
Brice
Sarah E
SE
Cowart
L Ashley
LA
Moye-Rowley
W Scott
WS
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; D026905:Amino Acid Transport Systems; D008565:Membrane Proteins; C092438:PDR5 protein, S cerevisiae; C465340:RSB1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C429825:TAT2 protein, S cerevisiae; D049452:Green Fluorescent Proteins; D014364:Tryptophan; C012491:phytosphingosine; D013110:Sphingosine
J Biol Chem. 2002 Aug 16;277(33):30048-54
12034738
Prog Lipid Res. 2006 Nov;45(6):447-65
16730802
Exp Cell Res. 2009 May 15;315(9):1574-83
19070615
FEMS Microbiol Rev. 2008 Jul;32(4):673-704
18559076
Mol Biol Cell. 2007 Jun;18(6):1979-91
17377064
Annu Rev Biochem. 2001;70:703-54
11395421
Science. 2005 Apr 22;308(5721):512-7
15845844
J Biol Chem. 2003 Sep 19;278(38):36041-50
12842877
J Bacteriol. 1983 Jan;153(1):163-8
6336730
Mol Biol Cell. 2000 Dec;11(12):4051-65
11102507
Mol Cell Biol. 2003 Nov;23(21):7566-84
14560004
Nature. 2009 May 21;459(7245):356-63
19458711
J Cell Biol. 2001 May 14;153(4):649-62
11352928
J Biol Chem. 1997 Oct 17;272(42):26087-90
9334171
Anal Biochem. 1988 Jun;171(2):373-81
3407935
Can J Biochem Physiol. 1959 Aug;37(8):911-7
13671378
Mol Biol Cell. 2004 Nov;15(11):4949-59
15342785
Mol Gen Genet. 1994 Aug 2;244(3):260-8
8058037
Mol Cell Biol. 1999 Apr;19(4):2998-3009
10082567
Mol Cell Biol. 1994 Oct;14(10):6597-606
7523855
Traffic. 2009 Dec;10(12):1856-67
19912579
J Cell Biol. 1995 Mar;128(5):779-92
7533169
J Cell Biol. 1999 Sep 20;146(6):1227-38
10491387
Annu Rev Biochem. 1987;56:615-49
3113327
Biochemistry. 2009 Jul 14;48(27):6390-401
19445518
Biochim Biophys Acta. 2007 Mar;1771(3):421-31
16997623
J Biol Chem. 1998 Jan 30;273(5):2829-34
9446592
Mol Biosyst. 2007 Dec;3(12):849-54
18000562
Mol Biol Cell. 2008 Nov;19(11):4640-50
18768750
J Biol Chem. 2009 Jul 3;284(27):17968-74
19416971
Cell. 2006 Jul 14;126(1):191-203
16839886
J Biol Chem. 2004 Aug 27;279(35):36720-31
15190065
J Cell Biol. 2003 Jun 23;161(6):1117-31
12810702
FEBS Lett. 2010 Jan 4;584(1):55-60
19944104
Annu Rev Physiol. 2007;69:483-510
17305471
J Biol Chem. 2006 Mar 10;281(10):6376-84
16407254
J Biol Chem. 2001 Sep 21;276(38):35614-21
11468289
FEMS Microbiol Lett. 2009 Sep;298(2):218-27
19659576
Mol Microbiol. 1998 Feb;27(3):643-50
9489675