![]()
|
|
||||||||
J. Biol. Chem., Vol. 275, Issue 46, 36369-36379, November 17, 2000
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From the Cell Biology Section, Laboratory of Parasitic Diseases,
Division of Intramural Research, NIAID, National Institutes of
Health, Bethesda, Maryland 20892-0425
The 3'-nucleotidase/nuclease (3'-NT/NU) is a
surface enzyme unique to trypanosomatid parasites. These organisms lack
the pathway for de novo purine biosynthesis and thus are
entirely dependent upon their hosts to supply this nutrient for their
survival, growth, and multiplication. The 3'-NT/NU is involved in the
salvage of preformed purines via the hydrolysis of either
3'-nucleotides or nucleic acids. In Crithidia luciliae,
this enzyme is highly inducible. For example, in these organisms purine
starvation triggers an ~1000-fold up-expression of 3'-NT/NU activity.
In the present study, we cloned and characterized a gene encoding this
intriguing enzyme from C. luciliae (Cl).
Sequence analysis showed that the Cl 3'-NT/NU deduced
protein possessed five regions, which we defined here as being
characteristic of members of the class I nuclease family. Further, we
demonstrated that the Cl 3'-NT/NU-expressed protein
possessed both 3'-nucleotidase and nuclease activities. Moreover, we
showed that the dramatic up-expression of 3'-NT/NU activity in response
to purine starvation of C. luciliae was concomitant with
the ~100-fold elevation in steady-state mRNA specific for this
gene. Finally, results of our nuclear run-on analyses demonstrated that
such up-regulation in 3'-NT/NU enzyme activity was mediated at the
posttranscriptional level.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBankTM/EMBL Data Bank with accession number(s) AF140355.
Molecular Characterization of a Hyperinducible, Surface
Membrane-anchored, Class I Nuclease of a Trypanosomatid Parasite*
,
*
The costs of publication of this
article were defrayed in part by the
payment of page charges. The article
must therefore be hereby marked
"advertisement" in
accordance with 18 U.S.C. Section
1734 solely to indicate this fact.
National Institutes of Health visiting fellow supported by
postdoctoral fellowships from the Fogarty International Center and the
NIAID, National Institutes of Health.
§
National Institutes of Health visiting associate supported by
postdoctoral fellowships from the Fogarty International Center and the
NIAID, National Institutes of Health. Present address: Laboratory of
Parasitic Biology and Biochemistry, Center for Biologics Evaluation and
Research, Food and Drug Administration, Bethesda, MD 20892.
¶
To whom correspondence should be addressed. Tel.:
301-496-5969; Fax: 301-402-2201; E-mail:
ddwyer@niaid.nih.gov.
This article has been cited by other articles:
![]() |
M. B. Joshi and D. M. Dwyer Molecular and Functional Analyses of a Novel Class I Secretory Nuclease from the Human Pathogen, Leishmania donovani J. Biol. Chem., March 30, 2007; 282(13): 10079 - 10095. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |