Comparative proteomic analysis of trophozoites versus cysts of Giardia lamblia.
The proteome of Giardia lamblia at its cyst stage was compared with that of trophozoites by using two-dimensional SDS-PAGE gel electrophoresis. Protein spots that increased in the extracts of cysts compared to trophozoites were identified by MALDI-TOF mass spectroscopy and categorized as cytoskeletal proteins, metabolic enzymes, a cell-cycle-specific kinase, stress resistance proteins, and a protein involved in translation. Expression patterns of five of the identified proteins were examined during encystation by real-time PCR. Expression of cwp1 (encoding cyst wall protein 1), a marker for encystation, was increased 11-fold. In contrast, tim (encoding triose-1-phosphate isomerase) was expressed constitutively during encystation, and its transcription level was therefore used as a mRNA loading control. Expression of three genes encoding beta-tubulin, vacuolar ATPase, and never-in-mitosis-A-related protein kinase did not vary significantly during encystation. Interestingly, genes encoding two heat shock proteins (Hsp70 and Hsp90) showed increased expression during encystation, suggesting that this differentiation process accompanies a cellular response to stress in G. lamblia.
Department of Environmental Medical Biology and Institute of Tropical Medicine, Post Brain Korea 21 Program, Yonsei University College of Medicine, Seoul 120-752, South Korea.
Juri
J
Kim
Sung-Su
SS
Bae
Moon-Hee
MH
Sung
Kyu-Ho
KH
Lee
Soon-Jung
SJ
Park
D000818:Animals; D003560:Cysts / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D016829:Giardia lamblia / Q000737:chemistry*; D016133:Polymerase Chain Reaction / Q000379:methods; D020543:Proteome / Q000032:analysis*; D015800:Protozoan Proteins / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053058:Trophozoites / Q000737:chemistry*
D020543:Proteome; D015800:Protozoan Proteins