title: Centrin in Giardia lamblia - ultrastructural localization.
abstract: Giardia lamblia is a multiflagellar parasite and one of the earliest diverging eukaryotic cells. It possesses a complex cytoskeleton based on different groups of microtubular structures - a ventral adhesive disc, four pairs of flagella, a median body and funis. Centrin is an important member of the EF-hand family of calcium-binding proteins, and it is known to show calcium-sensitive contractile behaviour. In the present study, we performed an ultrastructural localization of centrin in G. lamblia using several monoclonal antibodies to centrin. Microtubular structures such as the basal bodies, all the flagella axonemes, the adhesive disc, funis, and the median bodies presented positive labelling to centrin. In addition, the dense rods also demonstrated positive labelling. These results show that centrin is located in key positions related to microtubules. The role of centrin in these dynamic regions is discussed.
authors.affiliation: Laboratório de Ultraestrutura Celular, Universidade Santa Ursula, Rua Jornalista Orlando Dantas, 59 Botafogo, CEP 22231-010, Rio de Janeiro, Brazil.
authors.forename: Gladys
authors.initials: G
authors.lastname: Corrêa
authors.forename: José Andres
authors.initials: JA
authors.lastname: Morgado-Diaz
authors.forename: Marlene
authors.initials: M
authors.lastname: Benchimol
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000032:analysis*; D002467:Cell Nucleus / Q000737:chemistry / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis*; D003285:Contractile Proteins / Q000032:analysis; D003598:Cytoskeletal Proteins / Q000032:analysis; D003599:Cytoskeleton / Q000737:chemistry; D005407:Flagella / Q000737:chemistry / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D016829:Giardia lamblia / Q000737:chemistry / Q000648:ultrastructure*; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008870:Microtubules / Q000737:chemistry / Q000648:ultrastructure; D015388:Organelles / Q000737:chemistry / Q000648:ultrastructure; D015800:Protozoan Proteins / Q000032:analysis
chemical_list: D002135:Calcium-Binding Proteins; D002868:Chromosomal Proteins, Non-Histone; D003285:Contractile Proteins; D003598:Cytoskeletal Proteins; D015800:Protozoan Proteins; C056608:caltractin