title: Identification of α-11 giardin as a flagellar and surface component of Giardia lamblia.
abstract: Giardia lamblia is a protozoan pathogen with distinct cytoskeletal structures, including median bodies and eight flagella. In this study, we examined components comprising G. lamblia flagella. Crude flagellar extracts were prepared from G. lamblia trophozoites, and analyzed by two-dimensional (2-D) gel electrophoresis. The 19 protein spots were analyzed by MALDI-TOF mass spectrometry, identifying ten metabolic enzymes, six distinct giardins, Giardia trophozoite antigen 1, translational initiation factor eIF-4A, and an extracellular signal-regulated kinase 2. Among the identified proteins, we studied α-11 giardin which belongs to a group of cytoskeletal proteins specific to Giardia. Western blot analysis and real-time PCR indicated that expression of α-11 giardin is not significantly increased during encystation of G. lamblia. Immunofluorescence assays using anti-α-11 giardin antibodies revealed that α-11 giardin protein mainly localized to the plasma membranes and basal bodies of the anterior flagella of G. lamblia trophozoites, suggesting that α-11 giardin is a genuine component of the G. lamblia cytoskeleton.
authors.affiliation: Department of Environmental Medical Biology, Institute of Tropical Medicine, The Post Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 120-752, South Korea.
authors.forename: Juri
authors.initials: J
authors.lastname: Kim
authors.forename: Hye Yeon
authors.initials: HY
authors.lastname: Lee
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Lee
authors.forename: Tai-Soon
authors.initials: TS
authors.lastname: Yong
authors.forename: Kyu-Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Soon-Jung
authors.initials: SJ
authors.lastname: Park
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000276:immunology; D000918:Antibody Specificity; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry*; D003598:Cytoskeletal Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005407:Flagella / Q000737:chemistry*; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D016829:Giardia lamblia / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D015800:Protozoan Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; D003598:Cytoskeletal Proteins; D015800:Protozoan Proteins; C038207:giardin protein, Giardia lamblia
keywords: Cytoskeleton; Giardia lamblia; α-11 Giardin