N-myristoylation determines dual targeting of mammalian NADH-cytochrome b5 reductase to ER and mitochondrial outer membranes by a mechanism of kinetic partitioning.
Mammalian NADH-cytochrome b5 reductase (b5R) is an N-myristoylated protein that is dually targeted to ER and mitochondrial outer membranes. The N-linked myristate is not required for anchorage to membranes because a stretch of hydrophobic amino acids close to the NH2 terminus guarantees a tight interaction of the protein with the phospholipid bilayer. Instead, the fatty acid is required for targeting of b5R to mitochondria because a nonmyristoylated mutant is exclusively localized to the ER. Here, we have investigated the mechanism by which N-linked myristate affects b5R targeting. We find that myristoylation interferes with interaction of the nascent chain with signal recognition particle, so that a portion of the nascent chains escapes from cotranslational integration into the ER and can be post-translationally targeted to the mitochondrial outer membrane. Thus, competition between two cotranslational events, binding of signal recognition particle and modification by N-myristoylation, determines the site of translation and the localization of b5R.
Colombo
Sara
S
Consiglio Nazionale delle Ricerche Institute of Neuroscience, Cellular and Molecular Pharmacology Section and Department of Medical Pharmacology, University of Milan, 20129 Milan, Italy.
Longhi
Renato
R
Alcaro
Stefano
S
Ortuso
Francesco
F
Sprocati
Teresa
T
Flora
Adriano
A
Borgese
Nica
N
D000818:Animals; D042966:Cytochrome-B(5) Reductase / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism*; D019814:Myristic Acid / Q000378:metabolism*; D011487:Protein Conformation; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D018271:Signal Recognition Particle / Q000378:metabolism; D014162:Transfection
D012333:RNA, Messenger; D018271:Signal Recognition Particle; D019814:Myristic Acid; D042966:Cytochrome-B(5) Reductase
Trends Biochem Sci. 2001 Jan;26(1):61-6
11165519
Methods Enzymol. 1983;96:84-93
6656655
J Cell Biol. 1996 Jul;134(2):269-78
8707814
Methods Enzymol. 1983;96:682-91
6197610
Biochem Biophys Res Commun. 1981 Jul 30;101(2):591-8
7306098
Biochem J. 1990 Mar 1;266(2):341-7
2317190
Nature. 1986 Apr 17-23;320(6063):634-6
3010127
J Cell Biol. 1996 Dec;135(6 Pt 1):1501-13
8978818
J Neurochem. 2000 Jul;75(1):18-27
10854242
Am J Hum Genet. 1995 Aug;57(2):302-10
7668255
EMBO J. 1988 Jun;7(6):1769-75
3169004
Biochim Biophys Acta. 1999 Aug 12;1451(1):1-16
10446384
J Biol Chem. 2003 May 16;278(20):18628-37
12621052
Mol Cell Biol. 1988 Oct;8(10):4295-301
3141787
Int J Pept Protein Res. 1990 Mar;35(3):161-214
2191922
J Biol Chem. 2000 Oct 27;275(43):33820-7
10931837
Protein Sci. 1993 Oct;2(10):1559-73
8251932
EMBO J. 1996 Feb 1;15(3):468-78
8599930
Biochemistry. 1974 Jul 30;13(16):3350-9
4366945
Eur J Biochem. 1995 Jan 15;227(1-2):9-18
7851447
Trends Cell Biol. 1995 Jun;5(6):230-8
14732127
J Biol Chem. 1988 Feb 15;263(5):2127-33
3123489
Biochemistry. 1989 Feb 7;28(3):923-30
2653440
EMBO J. 2004 Jul 21;23(14):2755-64
15229647
Biochemistry. 2003 Oct 28;42(42):12154-62
14567676
J Cell Biol. 1987 Apr;104(4):855-63
3031084
J Mol Biol. 1987 Jun 5;195(3):621-36
2821280
J Biol Chem. 1984 Nov 10;259(21):13349-54
6436247
J Biol Chem. 1981 Jul 25;256(14):7187-92
6265441
Mol Biol Cell. 2002 Nov;13(11):3775-86
12429823
J Mol Biol. 1987 Jun 5;195(3):659-85
3656427
FEBS Lett. 1980 Apr 7;112(2):216-20
7371859
J Cell Biol. 2000 Oct 16;151(2):277-88
11038175
Nature. 1995 Aug 3;376(6539):444-7
7630423
Eur J Biochem. 1982 Feb;122(2):393-402
6800789
J Med Chem. 1985 Jul;28(7):849-57
3892003
J Biol Chem. 1993 Nov 5;268(31):23168-71
8226835
Cell. 1998 Jul 24;94(2):181-91
9695947
J Cell Biol. 1992 Jun;117(5):975-86
1577871
FEBS Lett. 2001 Aug 31;504(3):87-93
11532438
Subcell Biochem. 1993;21:313-41
8256272