Regulation of the mouse retinal taurine transporter (TAUT) by protein kinases in Xenopus oocytes

FEBS Letters

Loo, Donald D.F.¹  Sarkar, Hemanta K.²  Wright, Ernest M.¹  Hirsch, Jochen R.¹ 

[1] Department of Physiology, UCLA School of Medicine, Center for the Health Sciences, Los Angeles, CA 90095-1751, USA;Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030-9957, USA

关键词: Na+/Cl−/taurine cotransporter regulation;    Protein kinase activation;    Membrane trafficking;   

DOI  :  10.1016/0014-5793(96)00823-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The goal was to investigate the role of protein kinases in modulating taurine transporter activity in Xenopus laevis oocytes expressing the mouse retinal Na⁺/C⁻/taurine transporter. The currents generated by the taurine transporter were studied with a two-electrode voltage clamp and we recorded the maximal current (I _max ), presteady-state charge transfer Q, and membrane capacitance C _m . 8-BR-cAMP, a membrane-permeable activator of the cAMP-dependent protein kinase (PKA), decreased I _max (41%), Q (41%) and C _m (10%). Similarly, 1 μM sn-1,2-dioctanoylglycerol (DOG), an activator of the Ca²⁺ I diacylglycerol-dependent protein kinase (PKC), decreased I _max (56%), Q (37%), and C _m (9%). Calyculin A, a specific inhibitor of protein phosphatases 1 and 2A, also produced effects similar to those of 8-Br-cAMP and DOG, and decreased I _max (64%), Q (38%), and C _m (10%). We conclude that the taurine transporter is regulated by activators of PKA and PKC, and regulation occurs largely by changes in the number of transporters in the plasma membrane.

【 授权许可】

Unknown