TY - JOUR
T1 - Protein kinase B (PKB/Akt) is required for the completion of meiosis in mouse oocytes
AU - Hoshino, Yumi
AU - Sato, Eimei
N1 - Funding Information:
We thank Dr. Hiromichi Matsumoto of Utsunomiya University for the helpful discussions and Mr. Kentaro Inai of Tohoku University for teaching the microinjection technique to Y.H. This work was supported by the Japan Society for the Promotion of Science Grant JSPS-16108003 (to E.S.). This work was also supported in part by Research Fellowships for Young Scientists Program, JSPS-4892 (to Y.H.).
PY - 2008/2/1
Y1 - 2008/2/1
N2 - Akt, also known as protein kinase B, is implicated in many cellular processes. Akt is phosphorylated at two residues, Thr308 and Ser473. Thr308-phosphorylated Akt is present in pericentriolar materials, while localization of Ser473-phosphorylated Akt was similar to that of microtubules in metaphase oocytes. Spindles were shorter and aberrant in oocytes injected with Thr308- or Ser473-phosphorylated Akt antibodies. Specifically, Thr308- and Ser473-phosphorylated Akts function individually and are both necessary to assemble the metaphase II (MII) spindle. Moreover, the functions of Thr308- and Ser473-phosphorylated Akts differ in MII oocytes. Although oocytes exhibited second polar body (PB2) emission after the injection of a peptide for Thr308, the chromosomal alignment and microtubular organization were aberrant. In contrast, the injection of a peptide for Ser473 caused a failure of PB2 emission. These results suggest that Thr308- and Ser473-phosphorylated Akts are individually involved in fertilization to complete meiosis, including different roles (i.e., Ser473-phosphorylated Akts are involved in PB2 emission, whereas Thr308-phosphorylated Akts regulate the organization of microtubules).
AB - Akt, also known as protein kinase B, is implicated in many cellular processes. Akt is phosphorylated at two residues, Thr308 and Ser473. Thr308-phosphorylated Akt is present in pericentriolar materials, while localization of Ser473-phosphorylated Akt was similar to that of microtubules in metaphase oocytes. Spindles were shorter and aberrant in oocytes injected with Thr308- or Ser473-phosphorylated Akt antibodies. Specifically, Thr308- and Ser473-phosphorylated Akts function individually and are both necessary to assemble the metaphase II (MII) spindle. Moreover, the functions of Thr308- and Ser473-phosphorylated Akts differ in MII oocytes. Although oocytes exhibited second polar body (PB2) emission after the injection of a peptide for Thr308, the chromosomal alignment and microtubular organization were aberrant. In contrast, the injection of a peptide for Ser473 caused a failure of PB2 emission. These results suggest that Thr308- and Ser473-phosphorylated Akts are individually involved in fertilization to complete meiosis, including different roles (i.e., Ser473-phosphorylated Akts are involved in PB2 emission, whereas Thr308-phosphorylated Akts regulate the organization of microtubules).
KW - Akt/protein kinase B
KW - Fertilization
KW - Meiotic maturation
KW - Microinjection
KW - Mouse oocyte
KW - Peptide
KW - Polar body emission
KW - SH-6/Akt inhibitor III
KW - Spindle
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U2 - 10.1016/j.ydbio.2007.12.005
DO - 10.1016/j.ydbio.2007.12.005
M3 - Article
C2 - 18177853
AN - SCOPUS:38349088626
VL - 314
SP - 215
EP - 223
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 1
ER -