Related Experiment Video

Updated: Apr 12, 2026

Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei
08:44

Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei

Published on: January 22, 2019

7.9K

A component of the mitochondrial outer membrane proteome of T. brucei probably contains covalent bound fatty acids

Anna Albisetti1, Sebastian Wiese2, André Schneider1

  • 1Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern 3012, Switzerland.

Experimental Parasitology
|May 19, 2015
PubMed

Insights

Protein acylation, specifically myristoylation and palmitoylation, is crucial for the localization of Trypanosoma brucei POMP39 protein to cellular membranes. Disrupting acylation causes POMP39 to relocate to the cytosol without affecting parasite growth.

Area of Science:

  • Cell Biology
  • Parasitology
  • Biochemistry

Background:

  • Protein acylation, including myristoylation and palmitoylation, is a key post-translational modification in eukaryotes.
  • Acylation enables membrane association for proteins lacking transmembrane domains.
  • The outer mitochondrial membrane proteome (POMP) of Trypanosoma brucei includes proteins like POMP39.

Purpose of the Study:

  • To investigate the role of protein acylation in the localization and function of POMP39 in Trypanosoma brucei.
  • To determine the specific acylation sites and their contribution to POMP39's dual localization.

Main Methods:

  • Analysis of POMP39 localization using immunofluorescence microscopy.
  • Investigating the effects of global protein acylation inhibition and specific myristoylation site mutation on POMP39 localization.
  • Utilizing RNA interference (RNAi) to ablate POMP39 expression.

Main Results:

  • POMP39 is myristoylated and palmitoylated at its N-terminus and exhibits dual localization on mitochondria and flagella.
  • Inhibition of protein acylation or mutation of the myristoylation site leads to POMP39 relocation to the cytosol.
  • RNAi-mediated depletion of POMP39 did not result in observable growth phenotypes in either insect or bloodstream stages.

Conclusions:

  • N-terminal myristoylation and palmitoylation are essential for the membrane targeting of POMP39 in Trypanosoma brucei.
  • POMP39's dual localization is dependent on protein acylation, but the protein is non-essential for parasite viability under tested conditions.
Keywords:
African trypanosomesDual localization of proteinsMitochondrial outer membrane proteomeMyristoylation/palmitoylationProtein acylationProtein targeting

More Related Videos

Using Fluorescent Proteins to Monitor Glycosome Dynamics in the African Trypanosome10:04

Using Fluorescent Proteins to Monitor Glycosome Dynamics in the African Trypanosome

Published on: August 19, 2014

9.5K
Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae08:55

Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae

Published on: July 19, 2021

3.5K

Related Concept Videos

Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
18.0K
Mitochondrial Membranes01:45

Mitochondrial Membranes

2.4K
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death.  Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
6.0K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
13.8K
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria.  In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
5.1K
Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
5.2K