PKC-Mediated Modulation of Astrocyte SNAT3 Glutamine Transporter Function at Synapses in Situ.

Publisher: MDPI Country of Publication: Switzerland NLM ID: 101092791 Publication Model: Electronic Cited Medium: Internet ISSN: 1422-0067 (Electronic) Linking ISSN: 14220067 NLM ISO Abbreviation: Int J Mol Sci Subsets: MEDLINE

Original Publication: Basel, Switzerland : MDPI, [2000-

Amino Acid Transport Systems, Neutral/*metabolism ; Astrocytes/*metabolism ; Protein Kinase C/*metabolism ; Synapses/*metabolism; Animals ; Brain/metabolism ; Endocytosis ; Enzyme Activation ; Isoenzymes/metabolism ; Mice, Inbred C57BL ; Rats, Wistar

Astrocytes are glial cells that have an intimate physical and functional association with synapses in the brain. One of their main roles is to recycle the neurotransmitters glutamate and gamma-aminobutyric acid (GABA), as a component of the glutamate/GABA-glutamine cycle. They perform this function by sequestering neurotransmitters and releasing glutamine via the neutral amino acid transporter SNAT3. In this way, astrocytes regulate the availability of neurotransmitters and subsequently influence synaptic function. Since many plasma membrane transporters are regulated by protein kinase C (PKC), the aim of this study was to understand how PKC influences SNAT3 glutamine transport in astrocytes located immediately adjacent to synapses. We studied SNAT3 transport by whole-cell patch-clamping and fluorescence pH imaging of single astrocytes in acutely isolated brainstem slices, adjacent to the calyx of the Held synapse. Activation of SNAT3-mediated glutamine transport in these astrocytes was reduced to 77 ± 6% when PKC was activated with phorbol 12-myristate 13-acetate (PMA). This effect was very rapid (within ~20 min) and eliminated by application of bisindolylmaleimide I (Bis I) or 7-hydroxystaurosporine (UCN-01), suggesting that activation of conventional isoforms of PKC reduces SNAT3 function. In addition, cell surface biotinylation experiments in these brain slices show that the amount of SNAT3 in the plasma membrane is reduced by a comparable amount (to 68 ± 5%) upon activation of PKC. This indicates a role for PKC in dynamically controlling the trafficking of SNAT3 transporters in astrocytes in situ . These data demonstrate that PKC rapidly regulates the astrocytic glutamine release mechanism, which would influence the glutamine availability for adjacent synapses and control levels of neurotransmission.
Competing Interests: The authors declare no conflict of interest.

Cancer Res. 1992 May 15;52(10):2951-6. (PMID: 1316231)
Am J Physiol Endocrinol Metab. 2010 Mar;298(3):E395-402. (PMID: 19934406)
J Neurosci Res. 2015 Jul;93(7):1031-44. (PMID: 25648608)
Glia. 2017 Jun;65(6):900-916. (PMID: 28272791)
J Physiol. 2012 May 15;590(10):2317-31. (PMID: 22411007)
Nat Rev Neurosci. 2007 Dec;8(12):935-47. (PMID: 17987031)
Brain Res Mol Brain Res. 1997 Apr;45(1):90-8. (PMID: 9105674)
J Nutr. 2000 Apr;130(4S Suppl):1026S-31S. (PMID: 10736375)
Annu Rev Physiol. 2003;65:401-27. (PMID: 12524459)
J Cereb Blood Flow Metab. 2016 Nov;36(11):1929-1941. (PMID: 26661195)
Biochem Biophys Res Commun. 2003 Jun 20;306(1):156-62. (PMID: 12788082)
Prog Neurobiol. 2001 Sep;65(1):1-105. (PMID: 11369436)
Cell Tissue Res. 2006 Nov;326(2):311-37. (PMID: 16896951)
FEBS Lett. 2000 Mar 17;470(1):51-4. (PMID: 10722844)
J Neurosci. 2005 Sep 14;25(37):8482-97. (PMID: 16162930)
J Neurosci. 1999 Sep 15;19(18):7699-710. (PMID: 10479674)
J Neurochem. 2013 May;125(4):545-54. (PMID: 23418736)
J Neurochem. 2004 Jul;90(1):203-10. (PMID: 15198679)
J Neurosci. 1999 Jun 1;19(11):RC9. (PMID: 10341270)
J Biol Chem. 2012 Jun 1;287(23 ):19177-87. (PMID: 22505712)
Biochem J. 2008 Jun 15;412(3):495-506. (PMID: 18341477)
Glia. 2014 Jul;62(7):1093-109. (PMID: 24677092)
J Neurosci. 1990 Jul;10(7):2113-24. (PMID: 2376771)
Hippocampus. 1993 Jan;3(1):43-55. (PMID: 8364682)
J Neurosci. 2006 Aug 2;26(31):8195-205. (PMID: 16885233)
J Neurosci. 1997 Jan 1;17(1):45-57. (PMID: 8987735)
Am J Physiol Cell Physiol. 2010 Nov;299(5):C1047-57. (PMID: 20739622)
Front Endocrinol (Lausanne). 2013 Oct 02;4:138. (PMID: 24106489)
J Neurosci. 2011 Apr 27;31(17 ):6565-75. (PMID: 21525297)
EMBO J. 2001 Dec 17;20(24):7041-51. (PMID: 11742981)
Front Biosci (Landmark Ed). 2009 Jan 01;14:2386-99. (PMID: 19273207)
J Neurosci Methods. 1985 Nov-Dec;15(3):263-8. (PMID: 4094481)
Glia. 2011 Nov;59(11):1732-43. (PMID: 21812036)
J Neurosci Res. 1999 Aug 15;57(4):417-28. (PMID: 10440891)
Pharmacol Ther. 2004 Oct;104(1):17-27. (PMID: 15500906)
J Neurosci. 2003 Mar 1;23(5):1563-8. (PMID: 12629157)
J Pharmacol Exp Ther. 1998 Nov;287(2):744-51. (PMID: 9808705)
J Biol Chem. 1999 Dec 10;274(50):35794-801. (PMID: 10585462)
PLoS One. 2013;8(3):e58863. (PMID: 23484054)
J Comp Neurol. 2000 Nov 13;427(2):235-54. (PMID: 11054691)
Surgery. 1998 Aug;124(2):260-7; discussion 267-8. (PMID: 9706147)
Brain Res. 1991 May 17;549(1):106-11. (PMID: 1893244)
J Neurochem. 2002 Jan;80(1):1-11. (PMID: 11796738)
J Neurochem. 2007 Sep;102(6):1895-1904. (PMID: 17504265)
Cell Biochem Funct. 2003 Mar;21(1):1-9. (PMID: 12579515)
J Neurochem. 2003 Apr;85(2):503-14. (PMID: 12675927)
J Physiol. 2002 Feb 15;539(Pt 1):3-14. (PMID: 11850497)
Neuron. 2014 Feb 19;81(4):888-900. (PMID: 24559677)
J Neurosci. 2006 Aug 16;26(33):8537-48. (PMID: 16914680)
J Neurosci. 2008 Jan 2;28(1):264-78. (PMID: 18171944)
Glia. 2017 Sep;65(9):1491-1503. (PMID: 28581152)
Neuron. 1995 Sep;15(3):711-20. (PMID: 7546749)
Pharmacol Rev. 2016 Oct;68(4):888-953. (PMID: 27591044)
Glia. 2003 Feb;41(3):260-75. (PMID: 12528181)
Eur J Neurosci. 2002 May;15(10):1615-31. (PMID: 12059969)
Brain Res Dev Brain Res. 1994 Jul 15;80(1-2):19-25. (PMID: 7955344)
Brain Res. 1990 May 28;517(1-2):351-3. (PMID: 2376004)
J Neurosci. 2013 Oct 30;33(44):17429-34. (PMID: 24174676)
J Biol Chem. 2002 Nov 29;277(48):45741-50. (PMID: 12324450)
Neurochem Int. 2008 Mar-Apr;52(4-5):709-22. (PMID: 17919781)
FEBS Lett. 1995 Feb 13;359(2-3):259-61. (PMID: 7867810)
Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3230-5. (PMID: 10716701)
J Biol Chem. 2004 Apr 30;279(18):19315-26. (PMID: 14976208)
Glia. 2016 Oct;64(10 ):1655-66. (PMID: 26566753)
Synapse. 2011 Dec;65(12):1298-308. (PMID: 21656574)
Glia. 2010 Dec;58(16):1905-12. (PMID: 20737472)
Cell. 1999 Dec 23;99(7):769-80. (PMID: 10619430)
Glia. 2008 Jul;56(9):963-74. (PMID: 18381652)
Neurochem Int. 2008 Dec;53(6-8):296-308. (PMID: 18805448)
J Neurochem. 2006 Aug;98(3):641-53. (PMID: 16787421)
PLoS One. 2015 Sep 29;10(9):e0138897. (PMID: 26418248)
J Neurochem. 2006 May;97(4):911-21. (PMID: 16573659)
Prog Neurobiol. 1997 Mar;51(4):439-55. (PMID: 9106901)
J Neurochem. 2012 May;121(4):526-36. (PMID: 22339645)
J Neurosci Res. 1997 Nov 15;50(4):585-90. (PMID: 9404720)
Pflugers Arch. 2014 Jan;466(1):155-72. (PMID: 24193407)
Pflugers Arch. 2016 Feb;468(2):213-27. (PMID: 26490457)
Brain Res Mol Brain Res. 1998 May;56(1-2):108-17. (PMID: 9602083)
Pflugers Arch. 1998 Jul;436(4):615-22. (PMID: 9683736)

Keywords: Slc38a3; biotinylation; calyx of Held; glia; phorbol ester; phosphorylation; protein kinase C; protein trafficking; system N

0 (Amino Acid Transport Systems, Neutral)
0 (Isoenzymes)
0 (system N protein 1)
EC 2.7.11.13 (Protein Kinase C)

Date Created: 20180322 Date Completed: 20180903 Latest Revision: 20181114

20231215

PMC5979592

10.3390/ijms19040924

29561757