Molecular and functional characterization of galectin 9 mRNA isoforms in porcine and human cells and tissues.
To characterize the possible multiple implications of galectin 9, described as eosinophil chemoattractant protein as well as urate transporter/channel, the porcine homologue of galectin 9, Gal9p, was cloned from LLC-PK(1) cells and stably expressed in human embryonic kidney 293 cells. Significant Gal9p-mediated transport could be demonstrated for [(14)C]-uric acid and for [(14)C]-PAH(1). Transport was dependent on imposed changes of membrane potential of the host cells, but did not follow the classical carrier criteria. Gal9p-mRNA (1573 bp) as well as a 96 bp-elongated isoform show highest abundance in organs of the gastrointestinal tract, to a lesser extent in the aorta and the liver. RT-PCR on human tissue let to the identification of galectin 9 mRNA in human kidney, in HUVEC and in prototype cells of the monocyte/macrophage system (U-937, HL60). In HUVEC, three constitutively expressed galectin 9 mRNA-isoforms were identified. On the basis of the functional characteristics together with a detailed sequence analysis along the galectin family, different domains of galectin 9 are discussed. The data of the present study sustain the idea of the involvement of galectin 9 in immune/inflammation processes and in potential-sensitive uric acid translocation.
Spitzenberger
F
F
Department of Internal Medicine III, Pathological Biochemistry, Carl Gustav Carus Medical School, University of Technology Dresden, Dresden, Germany. juergen.graessler@mailbox.tu-dresden.de
Graessler
J
J
Schroeder
H E
HE
D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000737:chemistry; D004730:Endothelium, Vascular / Q000166:cytology; D037161:Galectins; D006801:Humans; D007668:Kidney / Q000166:cytology; D018374:LLC-PK1 Cells; D037102:Lectins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D027362:Organic Anion Transport Protein 1 / Q000378:metabolism; D027361:Organic Anion Transporters; D027701:Organic Cation Transport Proteins; D010957:Plasmids; D020033:Protein Isoforms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013552:Swine; D014018:Tissue Distribution; D014162:Transfection
D002352:Carrier Proteins; D002630:Chemotactic Factors; D037161:Galectins; C105032:LGALS9 protein, human; D037102:Lectins; C491242:Lgals9 protein, rat; D027362:Organic Anion Transport Protein 1; D027361:Organic Anion Transporters; D027701:Organic Cation Transport Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; C491241:SLC22A12 protein, human; C103862:urate transporter