Naegleria gruberi de novo basal body assembly occurs via stepwise incorporation of conserved proteins.
Centrioles and basal bodies are discrete structures composed of a cylinder of nine microtubule triplets and associated proteins. Metazoan centrioles can be found at mitotic spindle poles and are called basal bodies when used to organize microtubules to form the core structure of flagella. Naegleria gruberi, a unicellular eukaryote, grows as an amoeba that lacks a cytoplasmic microtubule cytoskeleton. When stressed, Naegleria rapidly (and synchronously) differentiates into a flagellate, forming a complete cytoplasmic cytoskeleton de novo, including two basal bodies and flagella. Here, we show that Naegleria has genes encoding conserved centriole proteins. Using novel antibodies, we describe the localization of three centrosomal protein homologs (SAS-6, gamma-tubulin, and centrin-1) during the assembly of the flagellate microtubule cytoskeleton. We also used these antibodies to show that Naegleria expresses the proteins in the same order as their incorporation into basal bodies, with SAS-6 localizing first, followed by centrin and finally gamma-tubulin. The similarities between basal body assembly in Naegleria and centriole assembly in animals indicate that mechanisms of assembly, as well as structure, have been conserved throughout eukaryotic evolution.
Fritz-Laylin
Lillian K
LK
Department of Molecular and Cell Biology, University of California-Berkeley, CA 94720, USA.
Assaf
Zoe June
ZJ
Chen
Sean
S
Cande
W Zacheus
WZ
D002454:Cell Differentiation; D002502:Centrioles / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D009253:Naegleria / Q000166:cytology* / Q000502:physiology; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*
D015800:Protozoan Proteins
J Cell Sci. 1968 Jun;3(2):207-30
5661997
Cell Motil Cytoskeleton. 2002 Jun;52(2):66-81
12112149
J Cell Biol. 2002 Sep 30;158(7):1171-81
12356862
Cell Motil Cytoskeleton. 1998;40(3):249-60
9678668
Leukemia. 2002 May;16(5):767-75
11986936
Curr Biol. 1999 Jan 14;9(1):43-6
9889124
Dev Biol. 1967 Feb;15(2):165-91
6068069
J Cell Biol. 1971 Dec;51(3):826-36
4942778
Nucleic Acids Res. 1998 Jan 1;26(1):320-2
9399864
J Mol Biol. 1990 Oct 5;215(3):403-10
2231712
Exp Parasitol. 2006 Feb;112(2):115-20
16321386
Curr Biol. 2007 Sep 4;17(17):1465-72
17689959
J Protozool. 1986 Aug;33(3):322-7
2427713
Gene. 2002 Jun 26;293(1-2):77-86
12137945
J Cell Biol. 2002 Sep 30;158(7):1195-206
12356864
Tissue Cell. 1975;7(1):1-11
1118856
J Cell Biol. 1984 Feb;98(2):449-56
6363422
Curr Opin Cell Biol. 2003 Feb;15(1):96-104
12517710
Trends Cell Biol. 2008 Aug;18(8):389-96
18620859
Nature. 2003 Dec 4;426(6966):570-4
14654843
Mol Biol Cell. 2009 Mar;20(6):1865-77
19158390
Cell Motil Cytoskeleton. 1996;33(4):298-323
8801035
Adv Exp Med Biol. 2007;607:119-29
17977464
Curr Biol. 2007 Dec 18;17(24):2169-74
18082404
Science. 2003 Jun 13;300(5626):1703-6
12805537
Nature. 2006 Nov 30;444(7119):619-23
17136092
J Cell Biol. 2007 Sep 10;178(6):905-12
17785518
Dev Cell. 2007 Aug;13(2):203-13
17681132
Curr Biol. 2001 Jun 26;11(12):R487-96
11448793
Curr Biol. 2005 Jun 21;15(12):1090-8
15964273
J Cell Biol. 1966 Oct;31(1):43-54
5971974