Summary: Centriole Duplication: Centrin in on
Luke M. Rice1 and David A. Agard1,2
Many aspects of centriole biology remain mysterious.
A new study has shed light on the role of the centrio-
lar protein centrin-2: reducing levels of centrin-2 in
HeLa cells has been found to block centriole dupli-
cation, eventually leading to cell death.
The centrosome is the microtubule organizing center of
most higher eukaryotic cells, and is generally described
as having two orthogonal centrioles surrounded by
pericentriolar material. This description highlights the
important role of centrioles as organizers of the peri-
centriolar material  that is primarily responsible for
coordinating the nucleation of microtubule assembly.
Indeed, initiation of centriole replication is one of the
earliest events in centrosome duplication. Centrioles
are multifunctional: in addition to organizing the centro-
some, they have recently been shown to play an impor-