XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Posters
29.
THE ROLE OF 14-3-3 PROTEIN IN REGULATION OF GLUCOSE
TraNSPORTER GLUT4 TraNSLOCATION TO ADIPOCYTE PLASMA
MEMBraNE
Lucia Gajdošechová, Miroslava Eckertová, Katarína Kršková and Štefan Zorad
Institute of Experimental Endocrinology, SAS, Bratislava, Slovakia
Basic mechanism of insulin action is translocation of GLUT4 transport vesicles (GTV) from
inner cell compartments to plasma membrane. Defect of this mechanism leads to development
of insulin resistance and diabetes. Beta isoform of 14-3-3 protein binds to Thrphosphorylated
AS160, the substrate of insulin-activated Akt protein kinase, thereby reducing
of AS160 GTP-ase activity and subsequently activating GTV translocation in adipose tissue.
The main purpose of the present study was to evaluate GLUT4 and GLUT1 transporters
protein content in epididymal adipose tissue plasma membranes of young obese Zucker
rats and correlate it with the amount of 14-3-3 protein in fat tisssue total homogenate.
Zucker rats represent a model of obesity and insulin resistance with mild hyperglycemia.
Based on unchanged GLUT1 and elevated GLUT4 content in plasma membrane fraction
of obese animals we assume normal insulin sensitivity with regard to glucose transporter
translocation in adipose tissue of 3-month-old obese Zucker rats. Augmented GLUT4
translocation seems to be due to an enormous increase in 14-3-3 protein which might play
a crucial role in glucose transporter activation. Surprisingly, the serum concentration of
adiponectin was significantly elevated in obese animals despite of decreased mRNA level
in white adipose tissue. The elucidation of 14-3-3 protein regulation, e.g. by adiponectin,
await for further investigation.
Ackowledgement: This work was supported by grant VEGA 2/0162/08.
XXII. Biochemistry Congress, Martin
147