Fw. Yu et al., Analysis of partner of inscuteable, a novel player of Drosophila asymmetric divisions, reveals two distinct steps in inscuteable apical localization, CELL, 100(4), 2000, pp. 399-409
Asymmetric localization is a prerequisite for inscuteable (insc) to functio
n in coordinating and mediating asymmetric cell divisions in Drosophila. We
show here that Partner of Inscuteable (Pins), a new component of asymmetri
c divisions, is required for Inscuteable to asymmetrically localize. In the
absence of pins, Inscuteable becomes cytoplasmic and asymmetric divisions
of neuroblasts and mitotic domain 9 cells show defects reminiscent of insc
mutants. Pins colocalizes with Insc and interacts with the region necessary
and sufficient for directing its asymmetric localization. Analyses of pins
function in neuroblasts reveal two distinct steps for Insc apical cortical
localization: A pins-independent, bazooka-dependent initiation step during
delamination (interphase) and a later maintenance step during which Baz, P
ins, and Insc localization are interdependent.