TY - JOUR
T1 - Regulatory contribution of heterotrimeric G-proteins to oocyte maturation in the sea urchin
AU - Voronina, Ekaterina
AU - Wessel, Gary M.
N1 - Funding Information:
The authors appreciate support and critical discussions provided by past and present members of PRovidence Institute of Molecular Oogenesis. We would like to thank Emma R. Green for help in cloning SpGα q and isolating SpGα i . We are grateful to Dr. Thomas Proschold for help in phylogenetic analysis of sea urchin Gα proteins. This work was supported by an NIH and an NSF grant to GMW.
PY - 2004/3
Y1 - 2004/3
N2 - Regulation of animal oocyte maturation is hypothesized to involve heterotrimeric G-proteins. It is difficult to test this hypothesis though without knowing what G-proteins are present in these cells and where are they localized. We set out to test the hypothesis that G-proteins regulate maturation in the sea urchin oocyte by identifying resident G-proteins in oocytes and eggs, and then investigating their function. We find four families of G-protein α-subunits (Gαi, Gαq, Gαs, and Gα12) present in both oocytes and eggs of the sea urchin. Three of them, Gαi, Gαq, and Gαs are present on the plasma membrane of the oocyte, while the fourth is located on cytoplasmic vesicles. Upon oocyte maturation, these proteins remain in eggs, and continue to be expressed in embryonic tissues. To test the functional contribution of the G-proteins to the regulation of oocyte maturation, we employ specific intervening reagents, including antibodies and competitor peptides to each Gα subunit, and specific Gα toxins. We find that Gi is a main candidate for a positive regulator of sea urchin oocyte maturation. These studies provide a foundation to further test specific hypotheses of the G-protein mediated regulation of oocyte maturation, fertilization, and early development in the sea urchin.
AB - Regulation of animal oocyte maturation is hypothesized to involve heterotrimeric G-proteins. It is difficult to test this hypothesis though without knowing what G-proteins are present in these cells and where are they localized. We set out to test the hypothesis that G-proteins regulate maturation in the sea urchin oocyte by identifying resident G-proteins in oocytes and eggs, and then investigating their function. We find four families of G-protein α-subunits (Gαi, Gαq, Gαs, and Gα12) present in both oocytes and eggs of the sea urchin. Three of them, Gαi, Gαq, and Gαs are present on the plasma membrane of the oocyte, while the fourth is located on cytoplasmic vesicles. Upon oocyte maturation, these proteins remain in eggs, and continue to be expressed in embryonic tissues. To test the functional contribution of the G-proteins to the regulation of oocyte maturation, we employ specific intervening reagents, including antibodies and competitor peptides to each Gα subunit, and specific Gα toxins. We find that Gi is a main candidate for a positive regulator of sea urchin oocyte maturation. These studies provide a foundation to further test specific hypotheses of the G-protein mediated regulation of oocyte maturation, fertilization, and early development in the sea urchin.
KW - Heterotrimeric G-proteins
KW - Meiosis
KW - Oocyte maturation
KW - Sea urchin
UR - http://www.scopus.com/inward/record.url?scp=1442274678&partnerID=8YFLogxK
U2 - 10.1016/j.mod.2004.01.005
DO - 10.1016/j.mod.2004.01.005
M3 - Article
C2 - 15003628
AN - SCOPUS:1442274678
SN - 0925-4773
VL - 121
SP - 247
EP - 259
JO - Mechanisms of Development
JF - Mechanisms of Development
IS - 3
ER -