Identification and characterization of an unusual class I myosin involved in vesicle traffic in Trypanosoma brucei.
Myosins are a multimember family of motor proteins with diverse functions in eukaryotic cells. African trypanosomes possess only two candidate myosins and thus represent a useful system for functional analysis of these motors. One of these candidates is an unusual class I myosin (TbMyo1) that is expressed at similar levels but organized differently during the life cycle of Trypanosoma brucei. This myosin localizes to the polarized endocytic pathway in bloodstream forms of the parasite. This organization is actin dependent. Knock down of TbMyo1 results in a significant reduction in endocytic activity, a cessation in cell division and eventually cell death. A striking morphological feature in these cells is an enlargement of the flagellar pocket, which is consistent with an imbalance in traffic to and from the surface. In contrast TbMyo1 is distributed throughout procyclic forms of the tsetse vector and a loss of approximately 90% of the protein has no obvious effects on growth or morphology. These results reveal a life cycle stage specific requirement for this myosin in essential endocytic traffic and represent the first description of the involvement of a motor protein in vesicle traffic in these parasites.
Spitznagel
Diana
D
Molecular Parasitology Group, School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland.
O'Rourke
John F
JF
Leddy
Neal
N
Hanrahan
Orla
O
Nolan
Derek P
DP
D000595:Amino Acid Sequence; D000818:Animals; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D024461:Myosin Type I / Q000097:blood / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D051381:Rats; D022161:Transport Vesicles / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000166:cytology* / Q000201:enzymology* / Q000378:metabolism
D024461:Myosin Type I
J Cell Sci. 2004 Mar 1;117(Pt 7):1105-15
14996937
J Cell Biol. 2000 Sep 4;150(5):1013-26
10973992
Nat Rev Mol Cell Biol. 2006 Dec;7(12):897-908
17139330
Traffic. 2004 Dec;5(12):905-13
15522093
Nature. 2005 Aug 25;436(7054):1113-8
16121172
FEBS Lett. 1987 Mar 23;213(2):316-8
3556584
Biochim Biophys Acta. 2000 Mar 17;1496(1):23-35
10722874
Mol Microbiol. 2008 May;68(4):933-46
18430083
Biochem J. 1979 Apr 15;180(1):11-24
486094
Acta Trop. 1979 Sep;36(3):289-92
43092
Traffic. 2003 Jun;4(6):358-66
12753645
Curr Biol. 1999 Oct 21;9(20):1169-72
10531030
J Cell Sci. 1990 Jun;96 ( Pt 2):249-55
2211865
Curr Opin Cell Biol. 2001 Feb;13(1):85-91
11163138
Mol Biol Cell. 1999 May;10(5):1477-94
10233157
J Cell Biol. 2000 Sep 4;150(5):F111-6
10974009
Mol Biol Cell. 2001 Apr;12(4):780-94
11294886
J Biol Chem. 1998 Jun 5;273(23):14644-8
9603982
FEBS J. 2009 Dec;276(23):7187-99
19895576
J Cell Sci. 2005 Oct 15;118(Pt 20):4823-32
16219689
Mol Biochem Parasitol. 2008 Feb;157(2):233-5
18061288
Proc Natl Acad Sci U S A. 2006 Mar 7;103(10):3681-6
16505385
Curr Biol. 2004 Sep 7;14(17):1604-9
15341750
Eukaryot Cell. 2004 Oct;3(5):1272-86
15470256
Proc Natl Acad Sci U S A. 2006 Aug 8;103(32):11928-33
16873553
EMBO J. 2004 Feb 25;23(4):780-9
14963487
Mol Biochem Parasitol. 1998 Mar 1;91(1):165-93
9574934
Curr Biol. 2004 Nov 23;14(22):R971-82
15556858
Proc Natl Acad Sci U S A. 2009 Jun 16;106(24):9685-90
19478066
J Cell Sci. 2004 Jul 1;117(Pt 15):3077-86
15226389
Mol Microbiol. 2004 Aug;53(3):735-44
15255888
Traffic. 2000 Jan;1(1):11-8
11208054
Bioinformatics. 2004 Feb 12;20(3):426-7
14960472
J Biol Chem. 2008 Feb 22;283(8):4520-7
18089562
Exp Parasitol. 1993 Jun;76(4):329-44
7685707
J Biol Chem. 2006 Sep 15;281(37):27600-12
16835237
Parasitol Today. 1999 Sep;15(9):365-71
10461165
FEBS Lett. 1995 Aug 1;369(1):67-71
7641887
Mol Microbiol. 1997 Oct;26(1):163-73
9383198
J Cell Biol. 1990 Aug;111(2):443-51
2143194
Cell Motil Cytoskeleton. 2003 Jan;54(1):29-40
12451593
J Biol Chem. 2002 Nov 8;277(45):42763-8
12221091
J Biol Chem. 2004 Feb 13;279(7):5958-66
14594806
Parasitol Today. 1994 Feb;10(2):80-4
15275508
Biochim Biophys Acta. 2006 Aug;1761(8):868-77
16644267
FEBS Lett. 2000 Nov 3;484(2):125-8
11068045
Trends Parasitol. 2002 Dec;18(12):540-6
12482539
Eukaryot Cell. 2009 Sep;8(9):1352-61
19581441
Syst Biol. 2003 Oct;52(5):696-704
14530136
J Cell Biol. 2008 Mar 24;180(6):1219-32
18347067
J Biol Chem. 2004 Mar 12;279(11):10692-701
14670954
J Biol Chem. 1999 Dec 3;274(49):35159-71
10574999
Bioinformatics. 1998;14(9):755-63
9918945
Mol Biol Cell. 2003 Feb;14(2):396-406
12589042
Trends Parasitol. 2004 Jan;20(1):13-6
14700584
Eukaryot Cell. 2007 Nov;6(11):2029-37
17905918
J Biol Chem. 1973 Jul 10;248(13):4682-90
4268863
Cell. 2003 Nov 14;115(4):475-87
14622601
Traffic. 2007 Jun;8(6):629-39
17461800
J Biol Chem. 1973 Jul 10;248(13):4691-7
4268864
J Cell Biol. 1992 Jun;117(6):1241-9
1607386
J Eukaryot Microbiol. 2000 May-Jun;47(3):191-6
10847335
Mol Biochem Parasitol. 2009 Apr;164(2):105-10
19121339
Cell Motil Cytoskeleton. 1989;13(3):127-44
2776221
J Mol Biol. 2005 May 27;349(1):113-25
15876372
Ann Trop Med Parasitol. 1995 Apr;89(2):105-11
7605118
Genes Dev. 2008 Feb 1;22(3):322-30
18230700
Nucleic Acids Res. 2004 Mar 19;32(5):1792-7
15034147
FEBS Lett. 2008 Jun 18;582(14):2112-9
18420037
Proc Natl Acad Sci U S A. 2009 Jul 21;106(29):11972-7
19574460
EMBO J. 2003 Oct 1;22(19):4991-5002
14517238