NuMA is a major acceptor of poly(ADP-ribosyl)ation by tankyrase 1 in mitosis.
Tankyrase 1 is a PARP [poly(ADP-ribose) polymerase] that localizes to multiple subcellular sites, including telomeres and mitotic centrosomes. Previous studies demonstrated that cells deficient in tankyrase 1 suffered a block in resolution of sister telomeres and arrested in early anaphase [Dynek and Smith (2004) Science 304, 97-100]. This phenotype was dependent on the catalytic PARP activity of tankyrase 1. To identify critical acceptors of PARsylation [poly(ADP-ribosyl)ation] by tankyrase 1 in mitosis, tankyrase 1 immunoprecipitates were analysed for associated PARsylated proteins. We identified NuMA (nuclear mitotic apparatus protein) as a major acceptor of poly(ADP-ribose) from tankyrase 1 in mitosis. We showed by immunofluorescence and immunoprecipitation that association between tankyrase 1 and NuMA increases dramatically at the onset of mitosis, concomitant with PARsylation of NuMA. Knockdown of tankyrase 1 by siRNA (small interfering RNA) eliminates PARsylation of NuMA in mitosis, confirming tankyrase 1 as the PARP responsible for this modification. However, even in the absence of tankyrase 1 and PARsylation, NuMA localizes to spindle poles. By contrast, siRNA knockdown of NuMA results in complete loss of tankyrase 1 from spindle poles. We discuss our result in terms of a model where PARsylation of NuMA by tankyrase 1 in mitosis could play a role in sister telomere separation and/or mitotic progression.
Chang
William
W
Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
Dynek
Jasmin N
JN
Smith
Susan
S
D034961:Antigens, Nuclear; D018797:Cell Cycle Proteins; D015971:Gene Expression Regulation, Enzymologic; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011485:Protein Binding; D034622:RNA Interference; D008941:Spindle Apparatus / Q000378:metabolism*; D038501:Tankyrases / Q000378:metabolism*
D034961:Antigens, Nuclear; D018797:Cell Cycle Proteins; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D011064:Poly Adenosine Diphosphate Ribose; D038501:Tankyrases; C050045:NUMA1 protein, human; C418109:TNKS protein, human