Solution structure of a novel Cdc42 binding module of Bem1 and its interaction with Ste20 and Cdc42.
Bem1 is a scaffold protein essential for the establishment of cell polarity in Saccharomyces cerevisiae. This work reports the solution structure of a Cdc42 binding module of Bem1 comprising the second SH3 domain (SH3b) and its C-terminal flanking region termed Cdc42 interacting (CI). First, the structure of Bem1 SH3b-CI was determined by NMR spectroscopy, which shows that Bem1 SH3b-CI is a structurally and functionally related domain that binds Cdc42. Next, the solution structure of Bem1 SH3b-CI in complex with the proline-rich region of p21-activated kinase Ste20 (Ste20 PRR) was determined. Finally, the interaction surface of Bem1 SH3b-CI with Cdc42 was identified based on chemical shift perturbation studies which reveals that Bem1 SH3b-CI interacts simultaneously with both Ste20 PRR and Cdc42 using the opposite surfaces. Thus, Bem1 can tether Cdc42 and Ste20 in close proximity so that Cdc42 can efficiently interact with Ste20 Cdc42 and Rac interactive binding (CRIB). Based on the present results together with the previous biochemical studies (Lamson, R. E., Winters, M. J., and Pryciak, P. M. (2002) Mol. Cell. Biol. 22, 2939-2951 and Winters, M. J., and Pryciak, P. M. (2005) Mol. Cell. Biol. 25, 2177-2190), a model was suggested that the autoinhibition of Ste20 kinase activity by CRIB is released through the Cdc42-CRIB interaction, which is mediated by Bem1, and Ste20 is subsequently activated, an initial step for the establishment of the cell polarity.
Takaku
Tomoyuki
T
Laboratory of Structural Biology, Graduate School of Life Science, Hokkaido University, N-12, W-6 Kita-ku, Sapporo 060-0812, Japan.
Ogura
Kenji
K
Kumeta
Hiroyuki
H
Yoshida
Naoki
N
Inagaki
Fuyuhiko
F
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry*; D000595:Amino Acid Sequence; D001671:Biochemistry / Q000379:methods; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D018360:Crystallography, X-Ray / Q000379:methods; D004926:Escherichia coli / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry*; D020930:MAP Kinase Kinase Kinases; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D011392:Proline / Q000737:chemistry; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D020764:cdc42 GTP-Binding Protein / Q000737:chemistry*
D048868:Adaptor Proteins, Signal Transducing; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; C073129:BEM1 protein, S cerevisiae; D011392:Proline; D017346:Protein Serine-Threonine Kinases; D020930:MAP Kinase Kinase Kinases; C078754:STE20 protein, S cerevisiae; D020764:cdc42 GTP-Binding Protein
J Biomol NMR. 1999 Mar;13(3):289-302
10212987
J Mol Biol. 1999 Sep 17;292(2):195-202
10493868
J Mol Biol. 1997 Oct 17;273(1):283-98
9367762
J Mol Graph. 1996 Feb;14(1):51-5, 29-32
8744573
J Biol Chem. 2003 Jan 10;278(2):843-52
12409291
EMBO J. 2003 Oct 1;22(19):4888-97
14517229
J Biomol NMR. 1995 Nov;6(3):277-93
8520220
EMBO J. 2002 Apr 2;21(7):1565-76
11927541
J Biochem. 2009 Sep;146(3):317-25
19451149
EMBO J. 2001 Aug 1;20(15):3947-56
11483498
J Biol Chem. 2001 Mar 9;276(10):7176-86
11113154
Mol Cell Biol. 2002 May;22(9):2939-51
11940652
J Biol Chem. 2007 Jan 5;282(1):29-38
17090539
Biochem J. 2005 May 15;388(Pt 1):177-84
15631622
J Cell Sci. 2001 Apr;114(Pt 7):1253-63
11256992
Annu Rev Cell Dev Biol. 1999;15:365-91
10611966
J Cell Sci. 2004 Mar 15;117(Pt 8):1291-300
15020669
EMBO J. 2001 Aug 1;20(15):3938-46
11483497
Mol Cell Biol. 2005 Mar;25(6):2177-90
15743816
J Biol Chem. 1994 Jan 28;269(4):2369-72
8300560
Mol Cell Biol. 1997 Sep;17(9):5067-76
9271384