title: Voltage sensitive phosphoinositide phosphatases of Xenopus: their tissue distribution and voltage dependence.
abstract: Voltage-sensitive phosphatases (VSPs) are unique proteins in which membrane potential controls enzyme activity. They are comprised of the voltage sensor domain of an ion channel coupled to a lipid phosphatase specific for phosphoinositides, and for ascidian and zebrafish VSPs, the phosphatase activity has been found to be activated by membrane depolarization. The physiological functions of these proteins are unknown, but their expression in testis and embryos suggests a role in fertilization or development. Here we investigate the expression pattern and voltage dependence of VSPs in two frog species, Xenopus laevis and Xenopus tropicalis, that are well suited for experimental studies of these possible functions. X. laevis has two VSP genes (Xl-VSP1 and Xl-VSP2), whereas X. tropicalis has only one gene (Xt-VSP). The highest expression of these genes was observed in testis, ovary, liver, and kidney. Our results show that while Xl-VSP2 activates only at positive membrane potentials outside of the physiological range, Xl-VSP1 and Xt-VSP phosphatase activity is regulated in the voltage range that regulates sperm-egg fusion at fertilization.
authors: Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06032, USA.
authors: William J
authors: WJ
authors: Ratzan
authors: Alexei V
authors: AV
authors: Evsikov
authors: Yasushi
authors: Y
authors: Okamura
authors: Laurinda A
authors: LA
authors: Jaffe
references: Gene Expr Patterns. 2011 Mar-Apr;11(3-4):233-8
references: 21172457
references: J Cell Biol. 1998 Oct 19;143(2):501-10
references: 9786958
references: J Gen Physiol. 2010 Feb;135(2):99-114
references: 20100891
references: J Biol Chem. 2008 Jun 27;283(26):18248-59
references: 18375390
references: Biochem J. 2001 Dec 1;360(Pt 2):277-83
references: 11716755
references: J Biol Chem. 2004 Feb 20;279(8):7037-47
references: 14660621
references: Dev Biol. 1982 Feb;89(2):475-84
references: 7056442
references: Nature. 2005 Jun 30;435(7046):1239-43
references: 15902207
references: Dev Biol. 1989 Aug;134(2):446-51
references: 2744242
references: Nature. 2002 Dec 5;420(6915):582-6
references: 12466854
references: Curr Biol. 1998 Mar 12;8(6):343-6
references: 9512420
references: J Biol Chem. 2001 Jun 15;276(24):21745-53
references: 11279206
references: Dev Genes Evol. 1996 Sep;206(2):110-24
references: 24173464
references: J Physiol. 2007 Sep 15;583(Pt 3):875-89
references: 17615106
references: Gene. 2003 Dec 24;323:189-99
references: 14659893
references: Proc Natl Acad Sci U S A. 2008 Jun 10;105(23):7970-5
references: 18524949
references: Dev Biol. 1983 Aug;98(2):319-26
references: 6683683
references: J Physiol (Paris). 1981 May;77(9):1113-7
references: 6286961
references: Dev Growth Differ. 2003 Apr;45(2):187-97
references: 12752506
references: J Immunol. 2008 Nov 15;181(10):6882-8
references: 18981107
references: Physiology (Bethesda). 2011 Feb;26(1):6-13
references: 21357898
references: Dev Biol. 1994 Dec;166(2):489-501
references: 7813772
references: Mol Biol Cell. 2001 Apr;12(4):1103-16
references: 11294910
references: Trends Biochem Sci. 2007 Jun;32(6):279-85
references: 17481902
references: Dev Biol. 1986 Sep;117(1):184-93
references: 3091428
references: Pflugers Arch. 2007 Jun;454(3):361-71
references: 17347852
references: Nature. 1976 May 6;261(5555):68-71
references: 944858
references: Dev Growth Differ. 1994 Oct;36(5):469-479
references: 37280968
references: Mol Biol Evol. 2007 Aug;24(8):1596-9
references: 17488738
references: Mol Reprod Dev. 2009 Sep;76(9):805-18
references: 19363788
references: J Cell Biol. 1982 Mar;92(3):616-21
references: 7085751
references: Genome Res. 1999 Sep;9(9):868-77
references: 10508846
references: J Gen Physiol. 2009 Jul;134(1):5-14
references: 19564425
references: Gene Expr Patterns. 2009 Dec;9(8):568-71
references: 19761872
references: Nat Rev Mol Cell Biol. 2008 Apr;9(4):323-32
references: 18354422
references: Nat Struct Mol Biol. 2008 Jan;15(1):106-8
references: 18084307
references: J Biol Chem. 2009 Jan 23;284(4):2106-13
references: 19047057
references: PLoS One. 2007 May 09;2(5):e440
references: 17487283
references: Hum Genet. 1999 Nov;105(5):399-409
references: 10598804