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Insulin regulates hSGLT2 expression via PKA and PKC activation
Author(s) -
Ghezzi Chiara,
Wright Ernest M
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1068.17
Subject(s) - protein kinase c , activator (genetics) , phosphorylation , incubation , insulin , chemistry , glucose transporter , medicine , endocrinology , microbiology and biotechnology , biology , biochemistry , receptor
Recent evidence suggest that in the rat proximal tubule SGLT2 (Sodium dependent Glucose Transporter 2) is phosphorylated. To test if human SGLT2 is regulated by posphorylation we analyze the effect of PKA and PKC activation on HEK‐293T cells expressing hSGLT2 using patch clamp and radio tracer uptake. PKA activation was induced by incubation of cells in 8‐bromoadenosine 3′‐5′‐cyclic monophosphate (Br‐cAMP) and sn‐1,2‐dioctanoylglycerol (DOG) was use as activator of PKC. After 1 h incubation in Br‐cAMP we observed a 2.5 fold increase in [ 14 C]α‐MDG uptake confirmed by a similar increase in glucose induced current. Incubation in DOG resulted in a 50 % increase in [ 14 C]α‐MDG uptake and glucose induced current. In both cases increase is caused by an increase in I max and not in the change in glucose affinity. These effects were completely suppressed by mutation of the SGLT2 phosphorylation site (S625A). In order to determine the initial event triggering the phosphorylation, we measured the effect of insulin on [ 14 C]α‐MDG uptake. Incubating cells expressing hSGLT2 wt or S625A mutant with 400 pM insulin induced a 3 fold increase in glucose transport in wild type hSGLT2 but not in the mutant. In conclusion our results indicate that insulin via PKA and PKC activation regulates hSGLT2 expression in a fast time scale by an increasing trafficking of hSGLT2 to the plasma membrane. NIH grant DK077133 and SNSF grant PBZHP3‐135919.