First published online June 1, 2005
Development 132, 1204e (2005)
© The Company of Biologists Limited
Anillins: versatile crosslinkers of the cytoskeleton
Anillins, conserved proteins that help stabilize and remodel the actin
cytoskeleton, have been implicated in cytokinesis in several systems and in
the cellularization of the syncytial Drosophila embryo. Two studies
now shed additional light on the role of anillins in contractile processes. On
p. 2849, Field et al.
report that in a series of Drosophila Anillin mutants, the ingression
of the furrows that form in the plasma membrane to create individual cells
during cellularization is slowed. Moreover, the new plasma membrane deposited
behind the furrows is unstable in these mutants. Anillin interacts with the
septins, GTPases that polymerize to form filaments and that concentrate in
ingressing furrows. Field et al. show that the severity of a mutant's
phenotype correlates with the extent of septin disruption, indicating that
septins are targeted to furrows by interacting with Anillin. On p.
2837, Maddox et al.
characterize two C. elegans anillin homologues, ANI-1 and ANI-2, that
have essential roles in the early embryo and gonad, respectively. ANI-1 is
required for the cytokinetic events that extrude the two polar bodies during
oocyte meiosis, and organizes myosin to produce cortical ruffles during
polarity establishment in the one-cell stage embryo. Like Drosophila
Anillin, ANI-1 is required to recruit septins to the base of ingressing
ruffles and to contractile rings, but both ANI-1 and the septins are
dispensable for mitotic cytokinesis in the early C. elegans embryo.
ANI-2 functions in the syncytial gonad of the adult worm, where nuclei
gradually cellularize to form oocytes. In ANI-2-depleted worms, the gonad
collapses and fails to produce oocytes of uniform size. Together, these papers
highlight the conserved roles of anillins in stabilizing membranes in
syncytial structures and in organizing cortical contractility, possibly by
acting as versatile crosslinkers of cortical cytoskeleton components.
Related articles in Development:
- Distinct roles for two C. elegans anillins in the gonad and early embryo
- Amy Shaub Maddox, Bianca Habermann, Arshad Desai, and Karen Oegema
Development 2005 132: 2837-2848.
[Abstract]
[Full Text]
- Characterization of anillin mutants reveals essential roles in septin localization and plasma membrane integrity
- Christine M. Field, Margaret Coughlin, Steve Doberstein, Thomas Marty, and William Sullivan
Development 2005 132: 2849-2860.
[Abstract]
[Full Text]
