title: Crotamine is a novel cell-penetrating protein from the venom of rattlesnake Crotalus durissus terrificus.
abstract: Herein we report that crotamine, a small lysine- and cysteine-rich protein from the venom of the South American rattlesnake, can rapidly penetrate into different cell types and mouse blastocysts in vitro. In vivo crotamine strongly labels cells from mouse bone marrow and spleen and from peritoneal liquid, as shown by fluorescent confocal laser-scanning microscopy. Nuclear localization of crotamine was observed in both fixed and unfixed cells. In the cytoplasm, crotamine specifically associates with centrosomes and thus allows us to follow the process of centriole duplication and separation. In the nucleus, it binds to the chromosomes at S/G2 phase, when centrioles start dividing. Moreover, crotamine appears as a marker of actively proliferating cells, as shown by 5-BrdU cell-proliferation assay. Crotamine in the micromolar range proved nontoxic to any of the cell cultures tested and did not affect the pluripotency of ES cells or the development of mouse embryos.
authors.affiliation: Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 277, 05508-900, São Paulo, SP, Brasil. akerkis@usp.br
authors.forename: Alexandre
authors.initials: A
authors.lastname: Kerkis
authors.forename: Irina
authors.initials: I
authors.lastname: Kerkis
authors.forename: Gandhi
authors.initials: G
authors.lastname: Rádis-Baptista
authors.forename: Eduardo B
authors.initials: EB
authors.lastname: Oliveira
authors.forename: Angela M
authors.initials: AM
authors.lastname: Vianna-Morgante
authors.forename: Lygia V
authors.initials: LV
authors.lastname: Pereira
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yamane
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002232:Carbocyanines / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D002463:Cell Membrane Permeability; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002502:Centrioles / Q000378:metabolism; D018385:Centrosome / Q000378:metabolism; D033481:Chromosomes, Mammalian / Q000378:metabolism; D003435:Crotalid Venoms / Q000737:chemistry* / Q000378:metabolism* / Q000633:toxicity*; D017839:Crotalus; D004622:Embryo, Mammalian / Q000166:cytology; D004625:Embryo, Nonmammalian; D006801:Humans; D051379:Mice; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects
chemical_list: D015415:Biomarkers; D002232:Carbocyanines; D003435:Crotalid Venoms; C089187:cyanine dye 3; C010563:crotamine