title: Cysteine protease inhibitor (AcStefin) is required for complete cyst formation of Acanthamoeba.
abstract: The encystation of Acanthamoeba leads to the formation of resilient cysts from vegetative trophozoites. This process is essential for parasite survival under unfavorable conditions, such as those associated with starvation, low temperatures, and biocides. Furthermore, cysteine proteases have been implicated in the massive turnover of intracellular components required for encystation. Thus, strict modulation of the activities of cysteine proteases is required to protect Acanthamoeba from intracellular damage. However, mechanisms underlying the control of protease activity during encystation have not been established in Acanthamoeba. In the present study, we identified and characterized Acanthamoeba cysteine protease inhibitor (AcStefin), which was found to be highly expressed during encystation and to be associated with lysosomes by fluorescence microscopy. Recombinant AcStefin inhibited various cysteine proteases, including human cathepsin B, human cathepsin L, and papain. Transfection with small interfering RNA against AcStefin increased cysteine protease activity during encystation and resulted in incomplete cyst formation, reduced excystation efficiency, and a significant reduction in cytoplasmic area. Taken together, these results indicate that AcStefin is involved in the modulation of cysteine proteases and that it plays an essential role during the encystation of Acanthamoeba.
authors: Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors: Jung-Yub
authors: JY
authors: Lee
authors: Su-Min
authors: SM
authors: Song
authors: Eun-Kyung
authors: EK
authors: Moon
authors: Yu-Ran
authors: YR
authors: Lee
authors: Bijay Kumar
authors: BK
authors: Jha
authors: Dinzouna-Boutamba Sylvatrie
authors: DB
authors: Danne
authors: Hee-Jae
authors: HJ
authors: Cha
authors: Hak Sun
authors: HS
authors: Yu
authors: Hyun-Hee
authors: HH
authors: Kong
authors: Dong-Il
authors: DI
authors: Chung
authors: Yeonchul
authors: Y
authors: Hong
mesh_terms: D048248:Acanthamoeba castellanii / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000235:genetics; D015891:Cystatins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D057056:Cysteine Proteases / Q000235:genetics / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006801:Humans; D008018:Life Cycle Stages / Q000235:genetics*; D008247:Lysosomes / Q000378:metabolism; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D016415:Sequence Alignment
chemical_list: D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D015800:Protozoan Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D002403:Cathepsins; D057056:Cysteine Proteases
references: Clin Microbiol Rev. 2003 Apr;16(2):273-307
references: 12692099
references: Parasitol Int. 2008 Dec;57(4):521-4
references: 18723116
references: Eukaryot Cell. 2006 May;5(5):836-48
references: 16682461
references: PLoS Pathog. 2010 Mar 26;6(3):e1000825
references: 20361051
references: Eur J Cell Biol. 1990 Oct;53(1):142-53
references: 2076701
references: Mol Biochem Parasitol. 2012 Jun;183(2):158-65
references: 22426571
references: Exp Parasitol. 1996 Oct;84(1):84-91
references: 8888735
references: Autophagy. 2008 Feb;4(2):151-75
references: 18188003
references: Mol Biochem Parasitol. 2005 Feb;139(2):197-203
references: 15664654
references: J Cell Sci. 2001 Nov;114(Pt 21):3933-42
references: 11719560
references: Mol Biol Cell. 2000 May;11(5):1789-800
references: 10793152
references: Mol Biochem Parasitol. 2009 Mar;164(1):86-94
references: 19111576
references: Protein Sci. 2002 Aug;11(8):1971-7
references: 12142451
references: Parasitol Res. 2006 Sep;99(4):323-4
references: 16636845
references: J Cell Sci. 2002 Dec 15;115(Pt 24):4993-5002
references: 12432085
references: Microbiol Mol Biol Rev. 1997 Sep;61(3):294-304
references: 9293183
references: FEBS Lett. 1991 Jul 22;285(2):213-9
references: 1855589
references: PLoS One. 2010 Mar 23;5(3):e9819
references: 20352108
references: Parasitol Res. 2006 Dec;100(1):171-4
references: 16802137
references: Exp Eye Res. 2002 Sep;75(3):285-93
references: 12384091
references: Eukaryot Cell. 2010 Apr;9(4):611-8
references: 20190073
references: PLoS Pathog. 2006 Nov;2(11):e117
references: 17083274
references: J Cell Biol. 1969 Jun;41(3):786-805
references: 5768875
references: Genomics. 1991 Jan;9(1):207-9
references: 2004763
references: FEBS Lett. 2006 Oct 2;580(22):5306-12
references: 16979632
references: Mol Biochem Parasitol. 2009 Nov;168(1):43-8
references: 19560492
references: Eukaryot Cell. 2003 Jun;2(3):501-9
references: 12796295
references: Cell. 1997 May 2;89(3):437-44
references: 9150143
references: FEBS Lett. 2003 May 8;542(1-3):12-6
references: 12729889
references: Eur J Immunol. 1997 Sep;27(9):2253-60
references: 9341767
references: FEBS Lett. 2005 Mar 14;579(7):1573-8
references: 15757643
references: Curr Biol. 2001 Mar 20;11(6):447-51
references: 11301256
references: Mol Biochem Parasitol. 2011 Jun;177(2):126-34
references: 21354219
references: Exp Cell Res. 1973 Jun;79(2):327-37
references: 4592913
references: Parasite Immunol. 2002 May;24(5):253-62
references: 12060319
references: Mol Microbiol. 2004 Dec;54(5):1224-36
references: 15554964
references: J Cell Sci. 2005 Mar 1;118(Pt 5):901-15
references: 15713748
references: Mol Biochem Parasitol. 2002 Mar;120(1):1-21
references: 11849701
references: J Protozool. 1973 Nov;20(5):654-7
references: 4763382
references: J Biol Chem. 2002 Mar 8;277(10):8474-81
references: 11773053
references: Exp Parasitol. 2008 May;119(1):111-6
references: 18280471
references: Wiad Parazytol. 1989;35(1):11-7
references: 2470206
references: Mol Biochem Parasitol. 2009 Sep;167(1):60-71
references: 19416741
references: J Immunol. 2001 Sep 15;167(6):3207-15
references: 11544307
references: Korean J Parasitol. 2011 Dec;49(4):341-7
references: 22355200
references: Annu Rev Microbiol. 1976;30:189-219
references: 791066
references: Dev Cell. 2004 Aug;7(2):167-78
references: 15296714
references: Nucleic Acids Res. 2004 Jan 1;32(Database issue):D160-4
references: 14681384
references: J Eukaryot Microbiol. 2001 Jan-Feb;48(1):11-6
references: 11249185
references: Mol Biochem Parasitol. 2012 Oct;185(2):121-6
references: 22917557
references: J Mol Biol. 1982 Jul 25;159(1):1-18
references: 6290670
references: Int J Parasitol. 2002 Feb;32(2):171-8
references: 11812494
references: EMBO J. 1990 Jun;9(6):1939-47
references: 2347312
references: Annu Rev Biophys Biomol Struct. 1999;28:181-204
references: 10410800
references: Infect Immun. 2008 Jan;76(1):278-88
references: 17923513
references: Cell Mol Life Sci. 2002 Sep;59(9):1503-12
references: 12440772
references: Infect Immun. 2003 May;71(5):2422-9
references: 12704112
references: Symp Soc Exp Biol. 1969;23:51-81
references: 4243920
references: J Biol Chem. 2008 Jun 27;283(26):18024-31
references: 18445589
references: Eur J Biochem. 1999 Sep;264(3):897-904
references: 10491138
references: Infect Immun. 2001 Dec;69(12):7380-6
references: 11705911