Bfa1 can regulate Tem1 function independently of Bub2 in the mitotic exit network of Saccharomyces cerevisiae

被引:38
作者
Ro, HS [1 ]
Song, S [1 ]
Lee, KS [1 ]
机构
[1] NCI, Lab Metab, Ctr Canc Res, NIH, Bethesda, MD 20892 USA
关键词
Cdc15; two-component GAP; budding yeast;
D O I
10.1073/pnas.062059999
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
In budding yeast, exit from mitosis is achieved by inactivation of Cdc28/Clb2 activity. Although it is not clear at present how mitotic exit is triggered, a growing body of evidence suggests that the Tem1 GTPase plays a critical role in mediating this pathway and that Bfa1 and Bub2 constitute a two-component GTPase-activating protein to negatively regulate Tem1. Here, we have demonstrated that introduction of bfa1Delta suppresses the growth defects associated with the cdc5-1 mutation significantly better than that of bub2Delta, suggesting that Bfa1 may have a previously uncharacterized role in this pathway. Overexpression of BFA1 efficiently arrested the cell cycle at postanaphase even in the absence of BUB2, whereas overexpression of BUB2 weakly induced mitotic arrest only in the presence of BFA1. Coimmunoprecipitation and in vitro binding studies indicate that Bfa1 binds strongly to Tem1 independently of Bub2. Provision of GDP+AlF4-, which mimics the GTPase transition state, enhanced the Bub2-Tem1 interaction both in vitro and in vivo. Interestingly, introduction of bfa1Delta, but not bub2Delta, greatly increased the interaction between Tem1 and Cdc15, a step that is thought to be critical for activating the mitotic exit network. Our data suggest that, in addition to its role as a putative, two-component GTPase-activating protein with Bub2, Bfa1 also can play a role in the regulation of mitotic exit by directly inhibiting the interaction between Tem1 and Cdc15 even in the absence of Bub2.
引用
收藏
页码:5436 / 5441
页数:6
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共 36 条
  • [1] Aluminium fluoride associates with the small guanine nucleotide binding proteins
    Ahmadian, MR
    Mittal, R
    Hall, A
    Wittinghofer, A
    [J]. FEBS LETTERS, 1997, 408 (03) : 315 - 318
  • [2] Asakawa K, 2001, GENETICS, V157, P1437
  • [3] A mechanism for coupling exit from mitosis to partitioning of the nucleus
    Bardin, AJ
    Visintin, R
    Amon, A
    [J]. CELL, 2000, 102 (01) : 21 - 31
  • [4] FLUOROALUMINATES ACTIVATE TRANSDUCIN-GDP BY MIMICKING THE GAMMA-PHOSPHATE OF GTP IN ITS BINDING-SITE
    BIGAY, J
    DETERRE, P
    PFISTER, C
    CHABRE, M
    [J]. FEBS LETTERS, 1985, 191 (02) : 181 - 185
  • [5] The spindle checkpoint of Saccharomyces cerevisiae responds to separable microtubule-dependent events
    Daum, JR
    Gomez-Ospina, N
    Winey, M
    Burke, DJ
    [J]. CURRENT BIOLOGY, 2000, 10 (21) : 1375 - 1378
  • [6] A Bub2p-dependent spindle checkpoint pathway regulates the Dbf2p kinase in budding yeast
    Fesquet, D
    Fitzpatrick, PJ
    Johnson, AL
    Kramer, KM
    Toyn, JH
    Johnston, LH
    [J]. EMBO JOURNAL, 1999, 18 (09) : 2424 - 2434
  • [7] Budding yeast Bub2 is localized at spindle pole bodies and activates the mitotic checkpoint via a different pathway from Mad2
    Fraschini, R
    Formenti, E
    Lucchini, G
    Piatti, S
    [J]. JOURNAL OF CELL BIOLOGY, 1999, 145 (05) : 979 - 991
  • [8] Regions of Byr4, a regulator of septation in fission yeast, that bind Spg1 or Cdc16 and form a two-component GTPase-activating protein with Cdc16
    Furge, KA
    Cheng, QC
    Jwa, M
    Shin, SJ
    Song, KW
    Albright, CF
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (16) : 11339 - 11343
  • [9] Byr4 and Cdc16 form a two-component GTPase-activating protein for the Spg1 GTPase that controls septation in fission yeast
    Furge, KA
    Wong, K
    Armstrong, J
    Balasubramanian, M
    Albright, CF
    [J]. CURRENT BIOLOGY, 1998, 8 (17) : 947 - 954
  • [10] Exit from mitosis: Spindle pole power
    Hoyt, MA
    [J]. CELL, 2000, 102 (03) : 267 - 270