Journal article icon

Journal article

Intracellular positioning of isoforms explains an unusually large adenylate kinase gene family in the parasite Trypanosoma brucei.

Abstract:
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 of gamma-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.
Publication status:
Published

Actions

Access Document

Publisher copy:
10.1074/jbc.m413821200

Authors


Journal:
Journal of biological chemistry More from this journal
Volume:
280
Issue:
12
Pages:
11781-11789
Publication date:
2005-03-01
DOI:
EISSN:
1083-351X
ISSN:
0021-9258


Language:
English
Keywords:
Pubs id:
pubs:29327
UUID:
uuid:ea0b774b-5734-44dc-ac16-79736cf073ed
Local pid:
pubs:29327
Source identifiers:
29327
Deposit date:
2012-12-19
ARK identifier:

Terms of use


Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP