title: Specific role of cytoplasmic dynein in the mechanism of action of an antitumor molecule, Amblyomin-X.
abstract: The Kunitz-type recombinant protein, Amblyomin-X, is an antitumor recombinant molecule from a cDNA library prepared from the salivary glands of the tick Amblyomma cajennense. The primary target of this protein appears to be the proteasome. Amblyomin-X increased gene and protein expression of distinct subunits of the molecular motor dynein, which plays a key role in the intracellular transport. Herein, Amblyomin-X was specifically taken up by tumor cells through lipid-raft endocytic pathways, but not by fibroblasts. Moreover, dynein inhibitor, ciliobrevin A, decreased Amblyomin-X uptake by tumor cells. Furthermore, incubation of tumor cells with Amblyomin-X inhibited trypsin-like activity of the proteasome, which was restored upon pretreatment with ciliobrevin A. Only in tumor cells treated with Amblyomin-X, we identified proteins bounds to dynein that are related to aggresome formation, autophagy inhibition, and early and recycling endosome markers. In addition, Amblyomin-X was found to interact with dynein, increased Rab11A protein expression and Rab11A co-localization with the light-intermediate chain 2 (LIC2) of dynein. Thereby, the results provide new insights on the antitumor mechanism of Amblyomin-X and reveal an unsuspected role of cytoplasmic dynein in its uptake, intracellular trafficking and pro-apoptotic action.
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil.
authors.forename: Mario T F
authors.initials: MT
authors.lastname: Pacheco
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil; Department of Biochemistry, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Kátia L P
authors.initials: KL
authors.lastname: Morais
authors.affiliation: Biochemistry Department, Institute of Chemistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Carolina M
authors.initials: CM
authors.lastname: Berra
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil.
authors.forename: Marilene
authors.initials: M
authors.lastname: Demasi
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil.
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Sciani
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil.
authors.forename: Vania G
authors.initials: VG
authors.lastname: Branco
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil.
authors.forename: Rosemary V
authors.initials: RV
authors.lastname: Bosch
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil.
authors.forename: Asif
authors.initials: A
authors.lastname: Iqbal
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, Brazil. Electronic address: ana.chudzinski@butantan.gov.br.
authors.forename: Ana Marisa
authors.initials: AM
authors.lastname: Chudzinski-Tavassi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D060829:Arthropod Proteins; D001343:Autophagy / Q000502:physiology; D045744:Cell Line, Tumor; D056445:Cytoplasmic Dyneins / Q000378:metabolism*; D006801:Humans; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000494:pharmacology*; D013987:Ticks
chemical_list: C559369:Amblyomin-X protein, Amblyomma cajennense; D060829:Arthropod Proteins; D011994:Recombinant Proteins; D012471:Salivary Proteins and Peptides; D046988:Proteasome Endopeptidase Complex; D056445:Cytoplasmic Dyneins
keywords: Amblyomin-X; Apoptosis; Autophagy; Cancer; Dynein; Endocytosis; Plasma membrane; Proteasome