Lethal giant larvae controls the localization of notch-signaling regulators numb, neuralized, and Sanpodo in Drosophila sensory-organ precursor cells.
Asymmetric distribution of fate determinants is a fundamental mechanism underlying the acquisition of distinct cell fates during asymmetric division. In Drosophila neuroblasts, the apical DmPar6/DaPKC complex inhibits Lethal giant larvae (Lgl) to promote the basal localization of fate determinants. In contrast, in the sensory precursor (pI) cells that divide asymmetrically with a planar polarity, Lgl inhibits Notch signaling in the anterior pI daughter cell, pIIb, by a yet-unknown mechanism. We show here that Lgl promotes the cortical recruitment of Partner of Numb (Pon) and regulates the asymmetric distribution of the fate determinants Numb and Neuralized during the pI cell division. Analysis of Pon-GFP and Histone2B-mRFP distribution in two-color movies confirmed that Lgl regulates Pon localization. Moreover, posterior DaPKC restricts Lgl function to the anterior cortex at mitosis. Thus, Lgl functions similarly in neuroblasts and in pI cells. We also show that Lgl promotes the acquisition of the pIIb cell fate by inhibiting the plasma membrane localization of Sanpodo and thereby preventing the activation of Notch signaling in the anterior pI daughter cell. Thus, Lgl regulates cell fate by controlling Pon cortical localization, asymmetric localization of Numb and Neuralized, and plasma-membrane localization of Sandopo.
Langevin
Johanna
J
Institut Curie, Unité mixte de recherche 144, 26 rue d'Ulm, 75248 Paris cedex 05, France.
Le Borgne
Roland
R
Rosenfeld
François
F
Gho
Michel
M
Schweisguth
François
F
Bellaïche
Yohanns
Y
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology*; D004330:Drosophila / Q000378:metabolism / Q000502:physiology*; D029721:Drosophila Proteins / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006657:Histones / Q000378:metabolism; D007150:Immunohistochemistry; D008840:Microfilament Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology; D021381:Protein Transport / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013234:Stem Cells / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
D002352:Carrier Proteins; D029721:Drosophila Proteins; D006657:Histones; D008840:Microfilament Proteins; C115164:PON protein, Drosophila; D025521:Tumor Suppressor Proteins; C081435:l(2)gl protein, Drosophila; C112833:spdo protein, Drosophila; D049452:Green Fluorescent Proteins; D044767:Ubiquitin-Protein Ligases; C071006:neur protein, Drosophila