Expression of multiple glutamate transporter splice variants in the rodent testis

• Published in: Asian journal of andrology Vol. 13; no. 2; pp. 254 - 265
• Main Authors: Lee, Aven, Anderson, Ashley R, Barnett, Amanda C, Chan, Anthony, Pow, David V
• Format: Journal Article
• Language: English
• Published: China Medknow Publications & Media Pvt. Ltd 01.03.2011; Nature Publishing Group
• Subjects: Alternative Splicing; Amino Acid Sequence; Amino Acid Transport System X-AG - genetics; Amino Acid Transport System X-AG - metabolism; Animals; Aspartic Acid - metabolism; Base Sequence; Brain - metabolism; DNA Primers - genetics; Excitatory Amino Acid Transporter 2 - genetics; Excitatory Amino Acid Transporter 2 - metabolism; Excitatory Amino Acid Transporter 3 - genetics; Excitatory Amino Acid Transporter 3 - metabolism; Excitatory Amino Acid Transporter 4 - genetics; Excitatory Amino Acid Transporter 4 - metabolism; Excitatory Amino Acid Transporter 5 - genetics; Excitatory Amino Acid Transporter 5 - metabolism; Gene Expression; Glutamic Acid - metabolism; Homeostasis; Immunohistochemistry; Male; Molecular Sequence Data; Original; PCR检测; Rats; Retina - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Testis - metabolism; 免疫细胞化学; 兴奋性氨基酸; 变异体; 谷氨酸转运体
• ISSN: 1008-682X; 1745-7262
• DOI: 10.1038/aja.2010.99

Glutamate is a regulated molecule in the mammalian testis. Extracellular regulation of glutamate in the body is determined largely by the expression of plasmalemmal glutamate transporters. We have examined by PCR, western blotting and immunocytochemistry the expression of a panel of sodium-dependent plasmalemmal glutamate transporters in the rat testis. Proteins examined included： glutamate aspartate transporter （GLAST）, glutamate transporter 1 （GLT1）, excitatory amino acid carrier 1 （EAAC1）, excitatory amino acid transporter 4 （EAAT4） and EAAT5. We demonstrate that many of the glutamate transporters in the testis are alternately spliced. GLAST is present as exon-3- and exon-9-skipping forms. GLT1 was similarly present as the alternately spliced forms GLT1 b and GLTlc, whereas the abundant brain form （GLTla） was detectable only at the mRNA level. EAAT5 was also strongly expressed, whereas EAAC1 and EAAT4 were absent. These patterns of expression were compared with the patterns of endogenous glutamate localization and with patterns of D-aspartate accumulation, as assessed by immunocytochemistry. The presence of multiple glutamate transporters in the testis, including unusually spliced forms, suggests that glutamate homeostasis may be critical in this organ. The apparent presence of many of these transporters in the testis and sperm may indicate a need for glutamate transport by such cells.