The sorting sequence of the peroxisomal integral membrane protein PMP47 is contained within a short hydrophilic loop.
No targeting sequence for peroxisomal integral membrane proteins has yet been identified. We have previously shown that a region of 67 amino acids is necessary to target Pmp47, a protein that spans the membrane six times, to peroxisomes. This region comprises two membrane spans and the intervening loop. We now demonstrate that the 20 amino acid loop, which is predicted to face the matrix, is both necessary and sufficient for peroxisomal targeting. Sufficiency was demonstrated with both chloramphenicol acetyltransferase and green fluorescent protein as carriers. There is a cluster of basic amino acids in the middle of the loop that we predict protrudes from the membrane surface into the matrix by a flanking stem structure. We show that the targeting signal is composed of this basic cluster and a block of amino acids immediately down-stream from it.
Dyer
J M
JM
Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235-9041, USA.
McNew
J A
JA
Goodman
J M
JM
D000595:Amino Acid Sequence; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006388:Hemagglutinins / Q000235:genetics; D008164:Luminescent Proteins; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008830:Microbodies / Q000378:metabolism*; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017384:Sequence Deletion
D005656:Fungal Proteins; D006388:Hemagglutinins; D008164:Luminescent Proteins; D008565:Membrane Proteins; C066456:PMP47 protein, Candida boidinii; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D015500:Chloramphenicol O-Acetyltransferase