title: Phosphorylation-dependent localization of the response regulator FrzZ signals cell reversals in Myxococcus xanthus.
abstract: The life cycle of Myxococcus xanthus includes co-ordinated group movement and fruiting body formation, and requires directed motility and controlled cell reversals. Reversals are achieved by inverting cell polarity and re-organizing many motility proteins. The Frz chemosensory pathway regulates the frequency of cell reversals. While it has been established that phosphotransfer from the kinase FrzE to the response regulator FrzZ is required, it is unknown how phosphorylated FrzZ, the putative output of the pathway, targets the cell polarity axis. In this study, we used Phos-tag SDS-PAGE to determine the cellular level of phospho-FrzZ under different growth conditions and in Frz signalling mutants. We detected consistent FrzZ phosphorylation, albeit with a short half-life, in cells grown on plates, but not from liquid culture. The available pool of phospho-FrzZ correlated with reversal frequencies, with higher levels found in hyper-reversing mutants. Phosphorylation was not detected in hypo-reversing mutants. Fluorescence microscopy revealed that FrzZ is recruited to the leading cell pole upon phosphorylation and switches to the opposite pole during reversals. These results are consistent with the hypothesis that the Frz pathway modulates reversal frequency through a localized response regulator that targets cell polarity regulators at the leading cell pole.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Kaimer
authors.forename: David R
authors.initials: DR
authors.lastname: Zusman
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D016764:Cell Polarity; D004591:Electrophoresis, Polyacrylamide Gel; D020869:Gene Expression Profiling; D008124:Locomotion; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D016941:Myxococcus xanthus / Q000502:physiology*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; C103380:FrzZ protein, Myxococcus xanthus
references.citation: Genes Dev. 2004 Mar 15;18(6):715-27
references.pmid: 15075296
references.citation: EMBO J. 2010 Jan 20;29(2):315-26
references.pmid: 19959988
references.citation: Annu Rev Genet. 2011;45:21-39
references.pmid: 21910630
references.citation: Mol Microbiol. 2010 Jun;76(6):1539-54
references.pmid: 20487265
references.citation: Proc Natl Acad Sci U S A. 2004 Dec 7;101(49):17084-9
references.pmid: 15569936
references.citation: J Bacteriol. 1991 Dec;173(23):7615-24
references.pmid: 1938957
references.citation: Proc Natl Acad Sci U S A. 2003 Apr 29;100(9):5443-8
references.pmid: 12704238
references.citation: Mol Gen Genet. 1985;198(2):243-54
references.pmid: 2984519
references.citation: J Bacteriol. 1982 Jun;150(3):1430-7
references.pmid: 6281244
references.citation: Proc Natl Acad Sci U S A. 2011 Feb 8;108(6):2498-503
references.pmid: 21248229
references.citation: J Mol Biol. 1978 Feb 25;119(2):167-78
references.pmid: 416222
references.citation: Proc Natl Acad Sci U S A. 2011 May 3;108(18):7559-64
references.pmid: 21482768
references.citation: J Bacteriol. 2012 Nov;194(21):5875-85
references.pmid: 22923595
references.citation: EMBO J. 2010 Jul 21;29(14):2276-89
references.pmid: 20543819
references.citation: J Biol Chem. 2007 Oct 5;282(40):29170-7
references.pmid: 17640875
references.citation: Mol Cell Proteomics. 2010 Jun;9(6):1133-43
references.pmid: 20097924
references.citation: FEBS Lett. 1995 Jan 16;358(1):31-3
references.pmid: 7821424
references.citation: Dev Biol. 1978 Jun;64(2):284-96
references.pmid: 98366
references.citation: Mol Microbiol. 2008 Aug;69(3):724-35
references.pmid: 18554333
references.citation: PLoS Biol. 2010 Jul 20;8(7):e1000430
references.pmid: 20652021
references.citation: Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):8787-91
references.pmid: 8415608
references.citation: Proc Natl Acad Sci U S A. 1985 Dec;82(24):8767-70
references.pmid: 3936045
references.citation: J Bacteriol. 1990 Sep;172(9):4877-87
references.pmid: 2168368
references.citation: Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3378-82
references.pmid: 8475084
references.citation: Science. 2005 Nov 4;310(5749):855-7
references.pmid: 16272122
references.citation: Curr Opin Microbiol. 2010 Apr;13(2):246-52
references.pmid: 20138001
references.citation: Nat Protoc. 2009;4(10):1513-21
references.pmid: 19798084
references.citation: Anal Biochem. 2008 May 1;376(1):73-82
references.pmid: 18328252
references.citation: PLoS Genet. 2012;8(8):e1002872
references.pmid: 22916026
references.citation: FEMS Microbiol Rev. 2012 Jan;36(1):149-64
references.pmid: 22091711
references.citation: Mol Microbiol. 2003 Mar;47(6):1695-708
references.pmid: 12622822
references.citation: J Bacteriol. 2005 Mar;187(5):1716-23
references.pmid: 15716443
references.citation: J Bacteriol. 1992 Jul;174(13):4246-57
references.pmid: 1624419
references.citation: Mol Microbiol. 2004 Jun;52(6):1799-811
references.pmid: 15186426
references.citation: Res Microbiol. 2012 Nov-Dec;163(9-10):579-91
references.pmid: 23123306
references.citation: Mol Microbiol. 2008 Jun;68(5):1328-39
references.pmid: 18430134
references.citation: Mol Microbiol. 2007 Jul;65(1):90-102
references.pmid: 17581122
references.citation: Proc Natl Acad Sci U S A. 1992 Jan 15;89(2):718-22
references.pmid: 1731345
references.citation: Nat Rev Microbiol. 2007 Nov;5(11):862-72
references.pmid: 17922045
references.citation: Proc Natl Acad Sci U S A. 2000 Aug 1;97(16):9098-103
references.pmid: 10922065
references.citation: Mol Microbiol. 1995 Nov;18(3):547-58
references.pmid: 8748037
references.citation: Science. 2007 Feb 9;315(5813):853-6
references.pmid: 17289998
references.citation: Mol Microbiol. 2004 Sep;53(5):1501-13
references.pmid: 15387825
references.citation: EMBO J. 2007 Oct 31;26(21):4433-44
references.pmid: 17932488
references.citation: Mol Microbiol. 1996 May;20(3):645-55
references.pmid: 8736543
references.citation: Mol Microbiol. 2009 Nov;74(3):691-706
references.pmid: 19775250
references.citation: PLoS Genet. 2012 Sep;8(9):e1002951
references.pmid: 23028358