Katanin, a microtubule-severing protein, is a novel AAA ATPase that targets to the centrosome using a WD40-containing subunit.
Microtubule disassembly at centrosomes is involved in mitotic spindle function. The microtubule-severing protein katanin, a heterodimer of 60 and 80 kDa subunits, was previously purified and shown to localize to centrosomes in vivo. Here we report the sequences and activities of the katanin subunits. p60 is a new member of the AAA family of ATPases, and we show that expressed p60 has microtubule-stimulated ATPase and microtubule-severing activities in the absence of p80. p80 is a novel protein containing WD40 repeats, which are frequently involved in protein-protein interactions. The p80 WD40 domain does not participate in p60 dimerization, but localizes to centrosomes in transfected mammalian cells. These results indicate katanin's activities are segregated into a subunit (p60) that possesses enzymatic activity and a subunit (p80) that targets the enzyme to the centrosome.
Hartman
J J
JJ
Department of Cellular and Molecular Pharmacology, University of California, San Francisco 94143, USA.
Mahr
J
J
McNally
K
K
Okawa
K
K
Iwamatsu
A
A
Thomas
S
S
Cheesman
S
S
Heuser
J
J
Vale
R D
RD
McNally
F J
FJ
D000251:Adenosine Triphosphatases / Q000032:analysis / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D018385:Centrosome / Q000201:enzymology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005347:Fibroblasts; D006801:Humans; D000074201:Katanin; D008854:Microscopy, Electron / Q000379:methods; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D012617:Sea Urchins; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D011993:Recombinant Fusion Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000074201:Katanin