Class I Arfs (Arf1 and Arf3) and Arf6 are localized to the Flemming body and play important roles in cytokinesis.
Small GTPases play important roles in various aspects of cell division as well as membrane trafficking. We and others previously showed that ADP-ribosylation factor 6 (Arf6) is locally activated around the ingressing cleavage furrow and recruited to the Flemming body in late cytokinesis phases, and involved in faithful completion of cytokinesis. However, knockout of the Arf6 gene or Arf6 depletion by siRNAs did not drastically influence cytokinesis. We here show that, in addition to Arf6, Class I Arfs (Arf1 and Arf3) are localized to the Flemming body, and that double knockdown of Arf1 and Arf3 moderately increases the proportion of multinucleate cells and simultaneous knockdown of Arf1, Arf3 and Arf6 leads to severe cytokinesis defects. These observations indicate that Arf1 and Arf3 as well as Arf6 play important roles in cytokinesis. We further show that EFA6 (exchange factor for Arf6) activates not only Arf6 but also Arf1 in the cell. Taken together with our previous data, these Arf GTPases are likely to be locally activated by EFA6 and in turn targeted to the Flemming body to complete cytokinesis.
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Ayako
A
Hanai
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Minako
M
Ohgi
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Chikako
C
Yagi
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Tomoko
T
Ueda
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Hye-Won
HW
Shin
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan kazunaka@pharm.kyoto-u.ac.jp.
Kazuhisa
K
Nakayama
D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism*; D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis; D055785:Gene Knockdown Techniques; D055786:Gene Knockout Techniques; D006056:Golgi Apparatus; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
D000089982:ADP-Ribosylation Factor 6; D020662:Guanine Nucleotide Exchange Factors; D009419:Nerve Tissue Proteins; C109970:PSD protein, human; D020033:Protein Isoforms; D034741:RNA, Small Interfering; C116687:ARF3 protein, human; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human
Arf1; Arf6; EFA6; Flemming body; cytokinesis