TY - JOUR
T1 - Epithelial Polarity Proteins Regulate Drosophila Tracheal Tube Size in Parallel to the Luminal Matrix Pathway
AU - Laprise, Patrick
AU - Paul, Sarah M.
AU - Boulanger, Jim
AU - Robbins, Renée M.
AU - Beitel, Greg J.
AU - Tepass, Ulrich
N1 - Funding Information:
We thank H. Hong for technical assistance. We are also grateful to E. Knust, M. Krasnow, H. Bellen, R. Fehon, the Developmental Studies Hybridoma Bank, and the Bloomington Drosophila Stock Center for reagents. Operating grants were provided by the Canadian Institutes of Health Research (to P.L. and U.T.) and the National Institutes of Health (R01 GM069540 to G.J.B. and Lung Biology Training Grant 5 T32 HL076139-0 to S.M.P.).
PY - 2010/1/12
Y1 - 2010/1/12
N2 - Regulation of epithelial tube size is critical for organ function. However, the mechanisms of tube size control remain poorly understood. In the Drosophila trachea, tube dimensions are regulated by a luminal extracellular matrix (ECM) [1-4]. ECM organization requires apical (luminal) secretion of the protein Vermiform (Verm), which depends on the basolateral septate junction (SJ) [5, 6]. Here, we show that apical and basolateral epithelial polarity proteins interact to control tracheal tube size independently of the Verm pathway. Mutations in yurt (yrt) and scribble (scrib), which encode SJ-associated polarity proteins [7, 8], cause an expansion of tracheal tubes but do not disrupt Verm secretion. Reducing activity of the apical polarity protein Crumbs (Crb) suppresses the length defects in yrt but not scrib mutants, suggesting that Yrt acts by negatively regulating Crb. Conversely, Crb overexpression increases tracheal tube dimensions. Reducing crb dosage also rescues tracheal size defects caused by mutations in coracle (cora), which encodes an SJ-associated polarity protein [8, 9]. In addition, crb mutations suppress cora length defects without restoring Verm secretion. Together, these data indicate that Yrt, Cora, Crb, and Scrib operate independently of the Verm pathway. Our data support a model in which Cora and Yrt act through Crb to regulate epithelial tube size.
AB - Regulation of epithelial tube size is critical for organ function. However, the mechanisms of tube size control remain poorly understood. In the Drosophila trachea, tube dimensions are regulated by a luminal extracellular matrix (ECM) [1-4]. ECM organization requires apical (luminal) secretion of the protein Vermiform (Verm), which depends on the basolateral septate junction (SJ) [5, 6]. Here, we show that apical and basolateral epithelial polarity proteins interact to control tracheal tube size independently of the Verm pathway. Mutations in yurt (yrt) and scribble (scrib), which encode SJ-associated polarity proteins [7, 8], cause an expansion of tracheal tubes but do not disrupt Verm secretion. Reducing activity of the apical polarity protein Crumbs (Crb) suppresses the length defects in yrt but not scrib mutants, suggesting that Yrt acts by negatively regulating Crb. Conversely, Crb overexpression increases tracheal tube dimensions. Reducing crb dosage also rescues tracheal size defects caused by mutations in coracle (cora), which encodes an SJ-associated polarity protein [8, 9]. In addition, crb mutations suppress cora length defects without restoring Verm secretion. Together, these data indicate that Yrt, Cora, Crb, and Scrib operate independently of the Verm pathway. Our data support a model in which Cora and Yrt act through Crb to regulate epithelial tube size.
KW - CELLBIO
KW - DEVBIO
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U2 - 10.1016/j.cub.2009.11.017
DO - 10.1016/j.cub.2009.11.017
M3 - Article
C2 - 20022244
AN - SCOPUS:73649136448
SN - 0960-9822
VL - 20
SP - 55
EP - 61
JO - Current Biology
JF - Current Biology
IS - 1
ER -