Molecular Biology of the Cell by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter by by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morg

PANEL 16–4 : Microtubules 933
MICROTUBULES
– +
γ-TuRC
nucleates assembly and
remains associated with
the minus end
centrosome
– +
stathmin
binds subunits,
prevents assembly
αβ-tubulin dimers
+TIPs
remain associated with growing plus ends
and can link them to other structures,
such as membranes
– +
microtubule
– +
XMAP215
kinesin-13
induces catastrophe
and disassembly
–
+
–
+
stabilizes plus ends
and accelerates assembly
katanin
severs microtubules
MAPs
stabilize microtubules by
binding along sides
filament bundling and cross-linking
tau MAP2 plectin
links to intermediate filaments
Some of the major accessory proteins of the microtubule cytoskeleton. Except for two classes of motor proteins,
an example of each major type is shown. Each of these is discussed in the text. However, most cells contain more
than a hundred different microtubule-binding proteins, and — as for the actin-associated proteins — it is likely
that there are important types of microtubule-associated proteins that are not yet recognized.