Differential phosphorylation at Ser473 and Thr308 of Akt-1 in rat brain following hypoglycemic coma.
We analyzed both total Akt-1 and phosphorylation of Akt-1 at residues Ser473 and Thr308 (phospho-Akt-1(Ser474) and phospho-Akt-1(Thr308), respectively) in the outer and inner layers of cortex following 30 min of hypoglycemic coma by Western blot analyses and confocal microscopy. The total amount of Akt-1 was not altered in any area examined. Phospho-Akt-1(Ser474), however, increased significantly in both layers of cortex at 0 and 30 min of recovery, but returned to control level at 3 h of recovery. In the vulnerable area (outer layer of cortex), no upregulation of phospho-Akt-1(Thr308) was observed at any time points examined. In the resistant area like inner layer of cortex, however, phospho-Akt-1(Thr308) was significantly over the control level at 3 h of recovery. Confocal microscopy result indicates that most of phospho-Akt-1(Thr308) had already moved into nucleus at 3 h of recovery. Our results suggest that Akt-1, when phosphorylated at Thr308, may play a protective role for neurons in the resistant regions of the brain.
Ouyang
Y B
YB
Center for the Study of Neurological Disease, The Queen's Medical Center, 1356 Lusitana Street, Honolulu, HI 96813, USA. yibing@cns.queens.org
Zhang
X H
XH
He
Q P
QP
Wang
G X
GX
Siesjö
B K
BK
Hu
B R
BR
D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D003128:Coma / Q000209:etiology* / Q000378:metabolism*; D007003:Hypoglycemia / Q000150:complications*; D008297:Male; D018613:Microscopy, Confocal; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014018:Tissue Distribution
D011518:Proto-Oncogene Proteins; C494920:Akt1 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt