M. Biermanns et J. Gartner, Targeting elements in the amino-terminal part direct the human 70-kDa peroxisomal integral membrane protein (PMP70) to peroxisomes, BIOC BIOP R, 285(3), 2001, pp. 649-655
Citations number
25
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Peroxisomes are multipurpose organelles present in nearly all eukaryotic ce
lls. All peroxisomale matrix and membrane proteins are synthesized in the c
ytoplasm. While a clear picture of the basic targeting mechanisms for perox
isomal matrix proteins has emerged over the past years, the targeting proce
sses for peroxisomal membrane proteins are poorly understood. The 70-kDa pe
roxisomal integral membrane protein (PMP70) is one of the proteins located
in the human peroxisome membrane. PMP70 belongs; to the family of ATP-bindi
ng cassette (ABC) transporter proteins. It consists of six transmembrane do
mains and an ATP-binding fold in the cytosol. Here we describe that efficie
nt peroxisomal targeting of human PMP70 depends on three targeting elements
in the aminoterminal protein region, namely amino acids 61 to 80 located i
n the cytosol as well as the first and second transmembrane domains. Furthe
rmore, peroxin 19 (PEX19) interactions are not required for targeting human
PMP70 to peroxisomes. PEX19 does not specifically bind to the targeting el
ements of human PMP70. (C) 2001 Academic Press.