Sequences required for the flagellar targeting of an integral membrane protein.
Previous studies have established that the ISO1 glucose transporter of Leishmania enriettii resides primarily in the flagellar membrane, whereas the ISO2 glucose transporter is located in the pellicular plasma membrane surrounding the cell body. This pronounced difference in subcellular targeting is conferred by the NH2-terminal domain of the transporters, since this is the only region of the two permeases that differs in sequence. Analysis of the 130 residue NH2-terminal domain of ISO1 using multiple terminal deletion mutants and various internal deletion mutants established that a sequence located between amino acids 84 and 100 of this domain is required for flagellar trafficking. In addition, chimeras between ISO1 and ISO2 indicated that the region between residues 110 and 118 of ISO1 is also required for flagellar targeting. These results imply that flagellar targeting information for this integral membrane protein does not constitute a simple linear sequence of amino acids but is at least bipartite in structure.
Department of Molecular Microbiology and Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239-3098, USA.
Marina Ignatushchenko Abdel
MI
Nasser
Scott M
SM
Landfear
D000595:Amino Acid Sequence; D000818:Animals; D005407:Flagella / Q000378:metabolism*; D017930:Genes, Reporter; D018313:Leishmania enriettii / Q000235:genetics* / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009004:Monosaccharide Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000235:genetics; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017384:Sequence Deletion
D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins