Molecular characterization of a glycerophosphoinositol transporter in mammalian cells.
The glycerophosphoinositols are ubiquitous phosphoinositide metabolites involved in the control of several cell functions. They exert their actions both intracellularly and by rapidly equilibrating across the plasma membrane when added to cells, implying the existence of a transporter for their membrane permeation. Such a transporter, GIT1, has been cloned in yeast. By PSI-BLAST analysis, we have identified the Glut2 transporter as a human-genome candidate ortholog of GIT1. This was supported directly through the use of inhibitors, siRNAs and competition studies of specific uptake of GroPIns in HeLa cells over-expressing human Glut2. These data identify Glut2 as a GroPIns transporter in mammals, and define a physiologically relevant cell-permeation mechanism.
Mariggiò
Stefania
S
Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Via Nazionale 8A, 66030 Santa Maria Imbaro (Chieti), Italy. mariggio@negrisud.it
Iurisci
Cristiano
C
Sebastià
Jordi
J
Patton-Vogt
Jana
J
Corda
Daniela
D
D000818:Animals; D002460:Cell Line; D015870:Gene Expression; D005944:Glucosamine / Q000378:metabolism; D051273:Glucose Transporter Type 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism*; D010693:Phloretin / Q000378:metabolism; D011485:Protein Binding; D034622:RNA Interference; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D051273:Glucose Transporter Type 2; D007295:Inositol Phosphates; C495680:SLC2A2 protein, human; D029701:Saccharomyces cerevisiae Proteins; C014575:glycerylphosphoinositol; D005944:Glucosamine; D010693:Phloretin