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Updated: Aug 10, 2026
09:43
Measurement of Heme Synthesis Levels in Mammalian Cells
Published on: July 9, 2015
On the biosynthesis of Rhodnius prolixus heme-binding protein
G O Paiva-Silva1, M H F Sorgine, C E Benedetti
1Departamento de Bioquímica Médica, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, CEP 21941-590, Rio de Janeiro, RJ, Brazil. gosilva@bioqmed.ufrj.br
Insect Biochemistry and Molecular Biology
|January 18, 2003
Summary
Rhodnius prolixus heme-binding protein (RHBP) is synthesized by fat bodies and secreted upon blood meal. Heme availability, not mRNA levels, controls RHBP synthesis post-transcriptionally.
Area of Science:
- Biochemistry
- Molecular Biology
- Insect Physiology
Background:
- Rhodnius prolixus heme-binding protein (RHBP) is found in hemolymph and oocytes.
- Its biosynthesis and regulation remain largely uncharacterized.
Purpose of the Study:
- To investigate the biosynthesis and regulation of RHBP in Rhodnius prolixus.
- To determine the role of heme in RHBP synthesis.
Main Methods:
- In vitro synthesis and secretion studies using 14C-leucine labeled fat bodies.
- RHBP titration with hemin.
- RHBP cDNA sequencing and Northern-blot analysis.
- Inhibition of heme biosynthesis using succinyl acetone (SA).
Main Results:
- Fat bodies synthesize and secrete 14C-RHBP, which is bound to heme.
- RHBP expression is restricted to fat bodies and increases post-blood meal.
- RHBP secretion and mRNA levels correlate with blood meal intake.
- SA treatment inhibits heme-RHBP secretion but not RHBP mRNA levels.
Conclusions:
- RHBP synthesis is regulated post-transcriptionally, with heme availability playing a key role.
- Fat body RHBP is secreted in a heme-bound form, indicating a specific regulatory mechanism.
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