INVESTIGADORES
PEREIRA Claudio Alejandro
artículos
Título:
Intracellular positioning of isoforms explains an unusually large adenylate kinase gene family in the parasite Trypanosoma brucei.
Autor/es:
GINGER, MICHAEL; ELISE NGAZOA,; PEREIRA, CA; TIMOTHY PULLEN,; MOSTAFA KABIRI,; KATJA BECKER,; GULL, KEITH; DIETMAR STEVERDING,
Revista:
JOURNAL OF BIOLOGICAL CHEMISTRY
Editorial:
The American Society for Biochemistry and Molecular Biology, Inc.
Referencias:
Año: 2005 vol. 280 p. 11781 - 11789
ISSN:
0021-9258
Resumen:
Adenylate kinases occur classically as cytoplasmic
and mitochondrial enzymes, but the expression of
seven adenylate kinases in the flagellated protozoan
parasite Trypanosoma brucei (order, Kinetoplastida;
family, Trypanosomatidae) easily exceeds the number
of isoforms previously observed within a single cell
and raises questions as to their location and function.
We show that a requirement to target adenylate kinase
into glycosomes, which are unique kinetoplastid-specific
microbodies of the peroxisome class in which
many reactions of carbohydrate metabolism are compartmentalized,
and two different flagellar structures
as well as cytoplasm and mitochondrion explains the
expansion of this gene family in trypanosomes. The
three isoforms that are selectively built into either the
flagellar axoneme or the extra-axonemal paraflagellar
rod, which is essential for motility, all contain long
N-terminal extensions. Biochemical analysis of the
only short form trypanosome adenylate kinase revealed
that this enzyme catalyzes phosphotransfer ofTrypanosoma brucei (order, Kinetoplastida;
family, Trypanosomatidae) easily exceeds the number
of isoforms previously observed within a single cell
and raises questions as to their location and function.
We show that a requirement to target adenylate kinase
into glycosomes, which are unique kinetoplastid-specific
microbodies of the peroxisome class in which
many reactions of carbohydrate metabolism are compartmentalized,
and two different flagellar structures
as well as cytoplasm and mitochondrion explains the
expansion of this gene family in trypanosomes. The
three isoforms that are selectively built into either the
flagellar axoneme or the extra-axonemal paraflagellar
rod, which is essential for motility, all contain long
N-terminal extensions. Biochemical analysis of the
only short form trypanosome adenylate kinase revealed
that this enzyme catalyzes phosphotransfer of
-phosphate from ATP to AMP, CMP, and UMP acceptors;
its high activity and specificity toward CMP is
likely to reflect an adaptation to very low intracellular
cytidine nucleotide pools. Analysis of some of the phosphotransfer
network using RNA interference suggests
considerable complexity within the homeostasis of cellular
energetics. The anchoring of specific adenylate
kinases within two distinct flagellar structures provides
a paradigm for metabolic organization and efficiency
in other flagellates.-phosphate from ATP to AMP, CMP, and UMP acceptors;
its high activity and specificity toward CMP is
likely to reflect an adaptation to very low intracellular
cytidine nucleotide pools. Analysis of some of the phosphotransfer
network using RNA interference suggests
considerable complexity within the homeostasis of cellular
energetics. The anchoring of specific adenylate
kinases within two distinct flagellar structures provides
a paradigm for metabolic organization and efficiency
in other flagellates.