TY - JOUR
T1 - Drosophila APC2 is a cytoskeletally-associated protein that regulates wingless signaling in the embryonic epidermis
AU - McCartney, Brooke M.
AU - Dierick, Herman A.
AU - Kirkpatrick, Catherine
AU - Moline, Melissa M.
AU - Baas, Annette
AU - Peifer, Mark
AU - Bejsovec, Amy
PY - 1999/9/20
Y1 - 1999/9/20
N2 - The tumor suppressor adenomatous polyposis coli (APC) negatively regulates Wingless (Wg)/Wnt signal transduction by helping target the Wnt effector β-catenin or its Drosophila homologue Armadillo (Arm) for destruction. In cultured mammalian cells, APC localizes to the cell cortex near the ends of microtubules. Drosophila APC (dAPC) negatively regulates Arm signaling, but only in a limited set of tissues. We describe a second fly APC, dAPC2, which binds Arm and is expressed in a broad spectrum of tissues. dAPC2's subcellular localization revealed colocalization with actin in many but not all cellular contexts, and also suggested a possible interaction with astral microtubules. For example, dAPC2 has a striking asymmetric distribution in neuroblasts, and dAPC2 colocalizes with assembling actin filaments at the base of developing larval denticles. We identified a dAPC2 mutation, revealing that dAPC2 is a negative regulator of Wg signaling in the embryonic epidermis. This allele acts genetically downstream of wg, and upstream of arm, dTCF, and, surprisingly, dishevelled. We discuss the implications of our results for Wg signaling, and suggest a role for dAPC2 as a mediator of Wg effects on the cytoskeleton. We also speculate on more general roles that APCs may play in cytoskeletal dynamics.
AB - The tumor suppressor adenomatous polyposis coli (APC) negatively regulates Wingless (Wg)/Wnt signal transduction by helping target the Wnt effector β-catenin or its Drosophila homologue Armadillo (Arm) for destruction. In cultured mammalian cells, APC localizes to the cell cortex near the ends of microtubules. Drosophila APC (dAPC) negatively regulates Arm signaling, but only in a limited set of tissues. We describe a second fly APC, dAPC2, which binds Arm and is expressed in a broad spectrum of tissues. dAPC2's subcellular localization revealed colocalization with actin in many but not all cellular contexts, and also suggested a possible interaction with astral microtubules. For example, dAPC2 has a striking asymmetric distribution in neuroblasts, and dAPC2 colocalizes with assembling actin filaments at the base of developing larval denticles. We identified a dAPC2 mutation, revealing that dAPC2 is a negative regulator of Wg signaling in the embryonic epidermis. This allele acts genetically downstream of wg, and upstream of arm, dTCF, and, surprisingly, dishevelled. We discuss the implications of our results for Wg signaling, and suggest a role for dAPC2 as a mediator of Wg effects on the cytoskeleton. We also speculate on more general roles that APCs may play in cytoskeletal dynamics.
KW - Adenomatous polyposis coli
KW - Armadillo
KW - Drosophila
KW - Wingless
KW - β-catenin
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UR - http://www.scopus.com/inward/citedby.url?scp=0033588939&partnerID=8YFLogxK
U2 - 10.1083/jcb.146.6.1303
DO - 10.1083/jcb.146.6.1303
M3 - Article
C2 - 10491393
AN - SCOPUS:0033588939
SN - 0021-9525
VL - 146
SP - 1303
EP - 1318
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 6
ER -