TY - JOUR
T1 - Three-dimensional models of proteases involved in patterning of the drosophila embryo
T2 - Crucial role of predicted cation binding sites
AU - Rose, Thierry
AU - LeMosy, Ellen K.
AU - Cantwell, Angelene M.
AU - Banerjee-Roy, Dolly
AU - Skeath, James B.
AU - Di Cera, Enrico
PY - 2003/3/28
Y1 - 2003/3/28
N2 - Three-dimensional models of the catalytic domains of Nudel (Ndl), Gastrulation Defective (Gd), Snake (Snk), and Easter (Ea), and their complexes with substrate suggest a possible organization of the enzyme cascade controlling the dorsoventral fate of the fruit fly embryo. The models predict that Gd activates Snk, which in turn activates Ea. Gd can be activated either autoproteolytically or by Ndl. The three-dimensional models of each enzyme-substrate complex in the cascade rationalize existing mutagenesis data and the associated phenotypes. The models also predict unanticipated features like a Ca2+ binding site in Ea and a Na+ binding site in Ndl and Gd. These binding sites are likely to play a crucial role in vivo as suggested by mutant enzymes introduced into embryos as mRNAs. The mutations in Gd that eliminate Na+ binding cause an apparent increase in activity, whereas mutations in Ea that abrogate Ca2+ binding result in complete loss of activity. A mutation in Ea predicted to introduce Na+ binding results in apparently increased activity with ventralization of the embryo, an effect not observed with wild-type Ea mRNA.
AB - Three-dimensional models of the catalytic domains of Nudel (Ndl), Gastrulation Defective (Gd), Snake (Snk), and Easter (Ea), and their complexes with substrate suggest a possible organization of the enzyme cascade controlling the dorsoventral fate of the fruit fly embryo. The models predict that Gd activates Snk, which in turn activates Ea. Gd can be activated either autoproteolytically or by Ndl. The three-dimensional models of each enzyme-substrate complex in the cascade rationalize existing mutagenesis data and the associated phenotypes. The models also predict unanticipated features like a Ca2+ binding site in Ea and a Na+ binding site in Ndl and Gd. These binding sites are likely to play a crucial role in vivo as suggested by mutant enzymes introduced into embryos as mRNAs. The mutations in Gd that eliminate Na+ binding cause an apparent increase in activity, whereas mutations in Ea that abrogate Ca2+ binding result in complete loss of activity. A mutation in Ea predicted to introduce Na+ binding results in apparently increased activity with ventralization of the embryo, an effect not observed with wild-type Ea mRNA.
UR - http://www.scopus.com/inward/record.url?scp=0038176533&partnerID=8YFLogxK
U2 - 10.1074/jbc.M211820200
DO - 10.1074/jbc.M211820200
M3 - Article
C2 - 12493753
AN - SCOPUS:0038176533
SN - 0021-9258
VL - 278
SP - 11320
EP - 11330
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 13
ER -