Functional expression of two glucose transporter isoforms from the parasitic protozoan Leishmania enriettii

Chris K. Langford, Brian M. Little, Michael P. Kavanaugh, Scott Landfear

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The parasitic protozoan Leishmania enriettii contains a family of tandemly repeated genes, designated Pro-1, that encode proteins with significant sequence similarity to mammalian facilitative glucose transporters. Pro-1 mRNAs are expressed almost exclusively in the promastigote or insect stage of the parasite life cycle. The Pro-1 tandem repeat encodes two isoforms of the putative transporter, iso-1 and iso-2, which have identical predicted amino acid sequences except for their NH2-terminal hydrophilic domains. We have now expressed both iso-1 and iso-2 by microinjecting their RNAs into Xenopus oocytes and assaying these oocytes for transport of various radiolabeled ligands. Both iso-1 and iso-2 transport [3H]2-deoxy-D-glucose, confirming that each protein is a bona fide glucose transporter. Each isoform also transports fructose and, to a much lesser degree, mannose. Compounds which inhibit 2-deoxy-D-glucose transport in L. enriettii promastigotes also inhibit transport in the microinjected oocytes expressing each isoform, indicating that the substrate specificities and pharmacological properties of each isoform are similar to those measured for 2-deoxy-D-glucose transport in intact parasites. The K(m) for transport of 2-deoxyglucose in oocytes expressing iso-1 is similar to that for oocytes expressing iso-2. These results reveal that both transporter isoforms have closely related functional properties and that the difference in their structures may serve some other purpose such as differential subcellular localization.

Original languageEnglish (US)
Pages (from-to)17939-17943
Number of pages5
JournalJournal of Biological Chemistry
Volume269
Issue number27
StatePublished - Jul 8 1994

Fingerprint

Leishmania enriettii
Facilitative Glucose Transport Proteins
Oocytes
Deoxyglucose
Protein Isoforms
Parasites
Tandem Repeat Sequences
Mannose
Substrate Specificity
Xenopus
Fructose
Life Cycle Stages
Insects
Life cycle
Amino Acid Sequence
Proteins
Genes
Pharmacology
RNA
Ligands

ASJC Scopus subject areas

  • Biochemistry

Cite this

Functional expression of two glucose transporter isoforms from the parasitic protozoan Leishmania enriettii. / Langford, Chris K.; Little, Brian M.; Kavanaugh, Michael P.; Landfear, Scott.

In: Journal of Biological Chemistry, Vol. 269, No. 27, 08.07.1994, p. 17939-17943.

Research output: Contribution to journalArticle

Langford, Chris K. ; Little, Brian M. ; Kavanaugh, Michael P. ; Landfear, Scott. / Functional expression of two glucose transporter isoforms from the parasitic protozoan Leishmania enriettii. In: Journal of Biological Chemistry. 1994 ; Vol. 269, No. 27. pp. 17939-17943.
@article{9cba329bd5a74a56a943c6a8b390699c,
title = "Functional expression of two glucose transporter isoforms from the parasitic protozoan Leishmania enriettii",
abstract = "The parasitic protozoan Leishmania enriettii contains a family of tandemly repeated genes, designated Pro-1, that encode proteins with significant sequence similarity to mammalian facilitative glucose transporters. Pro-1 mRNAs are expressed almost exclusively in the promastigote or insect stage of the parasite life cycle. The Pro-1 tandem repeat encodes two isoforms of the putative transporter, iso-1 and iso-2, which have identical predicted amino acid sequences except for their NH2-terminal hydrophilic domains. We have now expressed both iso-1 and iso-2 by microinjecting their RNAs into Xenopus oocytes and assaying these oocytes for transport of various radiolabeled ligands. Both iso-1 and iso-2 transport [3H]2-deoxy-D-glucose, confirming that each protein is a bona fide glucose transporter. Each isoform also transports fructose and, to a much lesser degree, mannose. Compounds which inhibit 2-deoxy-D-glucose transport in L. enriettii promastigotes also inhibit transport in the microinjected oocytes expressing each isoform, indicating that the substrate specificities and pharmacological properties of each isoform are similar to those measured for 2-deoxy-D-glucose transport in intact parasites. The K(m) for transport of 2-deoxyglucose in oocytes expressing iso-1 is similar to that for oocytes expressing iso-2. These results reveal that both transporter isoforms have closely related functional properties and that the difference in their structures may serve some other purpose such as differential subcellular localization.",
author = "Langford, {Chris K.} and Little, {Brian M.} and Kavanaugh, {Michael P.} and Scott Landfear",
year = "1994",
month = "7",
day = "8",
language = "English (US)",
volume = "269",
pages = "17939--17943",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "27",

}

TY - JOUR

T1 - Functional expression of two glucose transporter isoforms from the parasitic protozoan Leishmania enriettii

AU - Langford, Chris K.

AU - Little, Brian M.

AU - Kavanaugh, Michael P.

AU - Landfear, Scott

PY - 1994/7/8

Y1 - 1994/7/8

N2 - The parasitic protozoan Leishmania enriettii contains a family of tandemly repeated genes, designated Pro-1, that encode proteins with significant sequence similarity to mammalian facilitative glucose transporters. Pro-1 mRNAs are expressed almost exclusively in the promastigote or insect stage of the parasite life cycle. The Pro-1 tandem repeat encodes two isoforms of the putative transporter, iso-1 and iso-2, which have identical predicted amino acid sequences except for their NH2-terminal hydrophilic domains. We have now expressed both iso-1 and iso-2 by microinjecting their RNAs into Xenopus oocytes and assaying these oocytes for transport of various radiolabeled ligands. Both iso-1 and iso-2 transport [3H]2-deoxy-D-glucose, confirming that each protein is a bona fide glucose transporter. Each isoform also transports fructose and, to a much lesser degree, mannose. Compounds which inhibit 2-deoxy-D-glucose transport in L. enriettii promastigotes also inhibit transport in the microinjected oocytes expressing each isoform, indicating that the substrate specificities and pharmacological properties of each isoform are similar to those measured for 2-deoxy-D-glucose transport in intact parasites. The K(m) for transport of 2-deoxyglucose in oocytes expressing iso-1 is similar to that for oocytes expressing iso-2. These results reveal that both transporter isoforms have closely related functional properties and that the difference in their structures may serve some other purpose such as differential subcellular localization.

AB - The parasitic protozoan Leishmania enriettii contains a family of tandemly repeated genes, designated Pro-1, that encode proteins with significant sequence similarity to mammalian facilitative glucose transporters. Pro-1 mRNAs are expressed almost exclusively in the promastigote or insect stage of the parasite life cycle. The Pro-1 tandem repeat encodes two isoforms of the putative transporter, iso-1 and iso-2, which have identical predicted amino acid sequences except for their NH2-terminal hydrophilic domains. We have now expressed both iso-1 and iso-2 by microinjecting their RNAs into Xenopus oocytes and assaying these oocytes for transport of various radiolabeled ligands. Both iso-1 and iso-2 transport [3H]2-deoxy-D-glucose, confirming that each protein is a bona fide glucose transporter. Each isoform also transports fructose and, to a much lesser degree, mannose. Compounds which inhibit 2-deoxy-D-glucose transport in L. enriettii promastigotes also inhibit transport in the microinjected oocytes expressing each isoform, indicating that the substrate specificities and pharmacological properties of each isoform are similar to those measured for 2-deoxy-D-glucose transport in intact parasites. The K(m) for transport of 2-deoxyglucose in oocytes expressing iso-1 is similar to that for oocytes expressing iso-2. These results reveal that both transporter isoforms have closely related functional properties and that the difference in their structures may serve some other purpose such as differential subcellular localization.

UR - http://www.scopus.com/inward/record.url?scp=0028339806&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028339806&partnerID=8YFLogxK

M3 - Article

C2 - 8027051

AN - SCOPUS:0028339806

VL - 269

SP - 17939

EP - 17943

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 27

ER -