In vitro metacyclogenesis of Trypanosoma cruzi induced by starvation correlates with a transient adenylyl cyclase stimulation as well as with a constitutive upregulation of adenylyl cyclase expression.
The Trypanosoma cruzi adenylyl cyclase (AC) multigene family encodes different isoforms (around 15) sharing a variable large N-terminal domain, which is extracellular and receptor-like, followed by a transmembrane helix and a conserved C-terminal catalytic domain. It was proposed that these key enzymes in the cAMP signalling pathway allow the parasite to sense its changing extracellular milieu in order to rapidly adapt to its new environment, which is generally achieved through a differentiation process. One of the critical differentiation events the parasitic protozoan T. cruzi undergoes during its life cycle, known as metacyclogenesis, occurs in the digestive tract of the insect and corresponds to the differentiation from noninfective epimastigotes to infective metacyclic trypomastigote forms. By in vitro monitoring the activity of AC during metacyclogenesis, we showed that both the activity of AC and the intracellular cAMP content follow a similar pattern of transient stimulation in a two-step process, with a first activation peak occurring during the first hours of nutritional stress and a second peak between 6 and 48 h, corresponding to the cellular adhesion. During this differentiation process, a general mechanism of upregulation of AC expression of both mRNA and protein is triggered and in particular for a major subclass of these enzymes that are present in various gene copies commonly associated to the THT gene clusters. Although the scattered genome distribution of these gene copies is rather unusual in trypanosomatids and seems to be a recent acquisition in the evolution of the T. cruzi clade, their encoded product redistributed on the flagellum of the parasite upon differentiation could be important to sense the extracellular milieu.
Fiocruz, Instituto Oswaldo Cruz, Av. Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil.
Afsaneh
A
Hamedi
Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, Fiocruz, Av. Brasil 4365, 21040-900 Rio de Janeiro, Brazil.
Larisse
L
Botelho
Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, Fiocruz, Av. Brasil 4365, 21040-900 Rio de Janeiro, Brazil.
Constança
C
Britto
Instituto de Biologia Molecular do Paraná, Rua Professor Algacyr Munhoz Mader 3775, Curitiba 81350-010, PR, Brazil.
Stenio Perdigão
SP
Fragoso
Instituto Carlos Chagas, Fiocruz, PR, Rua Professor Algacyr Munhoz Mader 3775, Curitiba 81350-010, PR, Brazil.
Adriana Castilhos Souza
AC
Umaki
Instituto de Biologia Molecular do Paraná, Rua Professor Algacyr Munhoz Mader 3775, Curitiba 81350-010, PR, Brazil.
Samuel
S
Goldenberg
Université Libre de Bruxelles, Campus de la Plaine, Boulevard du Triomphe, 1050 Brussels, Belgium.
Guy
G
Bottu
Institute of Medical Biochemistry Leopoldo de Meis, Centro de Ciências e da Saúde, Federal University of Rio de Janeiro, Av. Brigadeiro Trompowsky, Rio de Janeiro 21941-590, Brazil. Electronic address: salmon@bioqmed.ufrj.br.
Didier
D
Salmon
D000262:Adenylyl Cyclases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D014355:Chagas Disease / Q000469:parasitology; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D008018:Life Cycle Stages; D008969:Molecular Sequence Data; D005810:Multigene Family; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015854:Up-Regulation
D020033:Protein Isoforms; D015800:Protozoan Proteins; D000262:Adenylyl Cyclases
Adenylyl cyclase; Metacyclogenesis; Parasite differentiation; T. cruzi; cAMP