Expression and function of glutamine transporters SN1 (SNAT3) and SN2 (SNAT5) in retinal Müller cells

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

PURPOSE. The expression and function of the glutamine transporters ATA1 and ATA2 (isoforms of system A), SN1 and SN2 (isoforms of system N), and LAT1 and LAT2 (isoforms of system L) were investigated in Müller cells in a rat Müller cell line (rMC1) and primary cultures of mouse Müller cells. METHODS. Glutamine uptake in rMC1 cells and primary Müller cells was measured. The relative contributions of various transport systems to glutamine uptake were determined based on the differential substrate specificities and Na+ dependence of individual transport systems. RT-PCR was used to analyze the expression of transporter-specific mRNAs. RESULTS. Three different transport systems participated in glutamine uptake in rMC1 cells: system L (Na+-independent), system A (Na+-dependent and α-(methylamino)isobutyric acid [MeAIB]-sensitive), and system N (Na +-dependent and MeAIB-insensitive). System N was the principal contributor (∼70%); the contributions of systems A and L were relatively lesser (20% and <10%, respectively). The functional features of Na +-dependent and MeAIB-insensitive glutamine uptake were similar to the known characteristics of clones of SN1 and SN2. Glutamine uptake in primary Müller cells behaved in a manner similar to that in rMC1 cells. mRNA transcripts specific for ATA1, ATA2, SN1, SN2, LAT1, and LAT2 were expressed in Müller cells. CONCLUSIONS. System N (SN1 as well as SN2) is responsible for most of the glutamine uptake in Müller cells. Because system N is capable of mediating the release of glutamine from the cells, its abundant expression in Müller cells is of importance in the handling of glutamine in the retina.

Original languageEnglish (US)
Pages (from-to)3980-3987
Number of pages8
JournalInvestigative Ophthalmology and Visual Science
Volume46
Issue number11
DOIs
StatePublished - Nov 1 2005

Fingerprint

Glutamine
Protein Isoforms
system N protein 1
Messenger RNA
Substrate Specificity
Retina
Clone Cells
Cell Line
Polymerase Chain Reaction

ASJC Scopus subject areas

  • Ophthalmology

Cite this

@article{5489a045ef734702a69284f3aed89bc1,
title = "Expression and function of glutamine transporters SN1 (SNAT3) and SN2 (SNAT5) in retinal M{\"u}ller cells",
abstract = "PURPOSE. The expression and function of the glutamine transporters ATA1 and ATA2 (isoforms of system A), SN1 and SN2 (isoforms of system N), and LAT1 and LAT2 (isoforms of system L) were investigated in M{\"u}ller cells in a rat M{\"u}ller cell line (rMC1) and primary cultures of mouse M{\"u}ller cells. METHODS. Glutamine uptake in rMC1 cells and primary M{\"u}ller cells was measured. The relative contributions of various transport systems to glutamine uptake were determined based on the differential substrate specificities and Na+ dependence of individual transport systems. RT-PCR was used to analyze the expression of transporter-specific mRNAs. RESULTS. Three different transport systems participated in glutamine uptake in rMC1 cells: system L (Na+-independent), system A (Na+-dependent and α-(methylamino)isobutyric acid [MeAIB]-sensitive), and system N (Na +-dependent and MeAIB-insensitive). System N was the principal contributor (∼70{\%}); the contributions of systems A and L were relatively lesser (20{\%} and <10{\%}, respectively). The functional features of Na +-dependent and MeAIB-insensitive glutamine uptake were similar to the known characteristics of clones of SN1 and SN2. Glutamine uptake in primary M{\"u}ller cells behaved in a manner similar to that in rMC1 cells. mRNA transcripts specific for ATA1, ATA2, SN1, SN2, LAT1, and LAT2 were expressed in M{\"u}ller cells. CONCLUSIONS. System N (SN1 as well as SN2) is responsible for most of the glutamine uptake in M{\"u}ller cells. Because system N is capable of mediating the release of glutamine from the cells, its abundant expression in M{\"u}ller cells is of importance in the handling of glutamine in the retina.",
author = "Siddaramappa, {Umapathy N} and Weiguo Li and Mysona, {Barbara A} and Smith, {Sylvia B} and Vadivel Ganapathy",
year = "2005",
month = "11",
day = "1",
doi = "10.1167/iovs.05-0488",
language = "English (US)",
volume = "46",
pages = "3980--3987",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "11",

}

TY - JOUR

T1 - Expression and function of glutamine transporters SN1 (SNAT3) and SN2 (SNAT5) in retinal Müller cells

AU - Siddaramappa, Umapathy N

AU - Li, Weiguo

AU - Mysona, Barbara A

AU - Smith, Sylvia B

AU - Ganapathy, Vadivel

PY - 2005/11/1

Y1 - 2005/11/1

N2 - PURPOSE. The expression and function of the glutamine transporters ATA1 and ATA2 (isoforms of system A), SN1 and SN2 (isoforms of system N), and LAT1 and LAT2 (isoforms of system L) were investigated in Müller cells in a rat Müller cell line (rMC1) and primary cultures of mouse Müller cells. METHODS. Glutamine uptake in rMC1 cells and primary Müller cells was measured. The relative contributions of various transport systems to glutamine uptake were determined based on the differential substrate specificities and Na+ dependence of individual transport systems. RT-PCR was used to analyze the expression of transporter-specific mRNAs. RESULTS. Three different transport systems participated in glutamine uptake in rMC1 cells: system L (Na+-independent), system A (Na+-dependent and α-(methylamino)isobutyric acid [MeAIB]-sensitive), and system N (Na +-dependent and MeAIB-insensitive). System N was the principal contributor (∼70%); the contributions of systems A and L were relatively lesser (20% and <10%, respectively). The functional features of Na +-dependent and MeAIB-insensitive glutamine uptake were similar to the known characteristics of clones of SN1 and SN2. Glutamine uptake in primary Müller cells behaved in a manner similar to that in rMC1 cells. mRNA transcripts specific for ATA1, ATA2, SN1, SN2, LAT1, and LAT2 were expressed in Müller cells. CONCLUSIONS. System N (SN1 as well as SN2) is responsible for most of the glutamine uptake in Müller cells. Because system N is capable of mediating the release of glutamine from the cells, its abundant expression in Müller cells is of importance in the handling of glutamine in the retina.

AB - PURPOSE. The expression and function of the glutamine transporters ATA1 and ATA2 (isoforms of system A), SN1 and SN2 (isoforms of system N), and LAT1 and LAT2 (isoforms of system L) were investigated in Müller cells in a rat Müller cell line (rMC1) and primary cultures of mouse Müller cells. METHODS. Glutamine uptake in rMC1 cells and primary Müller cells was measured. The relative contributions of various transport systems to glutamine uptake were determined based on the differential substrate specificities and Na+ dependence of individual transport systems. RT-PCR was used to analyze the expression of transporter-specific mRNAs. RESULTS. Three different transport systems participated in glutamine uptake in rMC1 cells: system L (Na+-independent), system A (Na+-dependent and α-(methylamino)isobutyric acid [MeAIB]-sensitive), and system N (Na +-dependent and MeAIB-insensitive). System N was the principal contributor (∼70%); the contributions of systems A and L were relatively lesser (20% and <10%, respectively). The functional features of Na +-dependent and MeAIB-insensitive glutamine uptake were similar to the known characteristics of clones of SN1 and SN2. Glutamine uptake in primary Müller cells behaved in a manner similar to that in rMC1 cells. mRNA transcripts specific for ATA1, ATA2, SN1, SN2, LAT1, and LAT2 were expressed in Müller cells. CONCLUSIONS. System N (SN1 as well as SN2) is responsible for most of the glutamine uptake in Müller cells. Because system N is capable of mediating the release of glutamine from the cells, its abundant expression in Müller cells is of importance in the handling of glutamine in the retina.

UR - http://www.scopus.com/inward/record.url?scp=33644686858&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33644686858&partnerID=8YFLogxK

U2 - 10.1167/iovs.05-0488

DO - 10.1167/iovs.05-0488

M3 - Article

VL - 46

SP - 3980

EP - 3987

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 11

ER -