Tissue specific variants of glutamate transporter GLT-1.
cDNA cloning of glutamate transporter GLT-1 from mouse brain and liver has revealed that 5'-ends of the messages are different between brain and liver. In addition, one of the GLT-1 cDNAs isolated from liver has been found to possess a 3'-end different from those of the others. Reverse transcription polymerase chain reaction (RT-PCR) amplification using primers specific for altered 5'-ends has confirmed that brain and liver messages possess their own specific 5'-ends. Both of the two 3'-ends have been demonstrated by RT-PCR to be present not only in liver but also in brain, indicating both brain and liver GLT-1 possess two types of 3'-ends. Although functional properties are not changed by the alteration of N-termini and C-termini when expressed in Xenopus laevis oocytes, co-expression of two liver type GLT-1 with different C-termini (mGLT-1A and mGLT-1B) has been found to result in the increase in Vmax of transport without changing Km. These results suggest the tissue specific alternative splicing at 5'-ends of GLT-1 messages and the interesting association of spliced variants with different C-termini.
Utsunomiya-Tate
N
N
Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
Endou
H
H
Kanai
Y
Y
D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis* / Q000737:chemistry / Q000502:physiology; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D027322:Amino Acid Transport System X-AG; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D005260:Female; D014644:Genetic Variation; D018698:Glutamic Acid / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009865:Oocytes / Q000502:physiology; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014982:Xenopus laevis
D018528:ATP-Binding Cassette Transporters; D027322:Amino Acid Transport System X-AG; D017931:DNA Primers; D012333:RNA, Messenger; D011994:Recombinant Proteins; D018698:Glutamic Acid