Acid Vesicles

Author: Gianpiero Pescarmona
Date: 18/03/2007


Functions of acidic vesicles

Functions: endocytosis-and-exocytosis

The PrP recycling

Kegg Pathways: Lysosomes

The pH range of acidic vesicles

Citron kinase, a RhoA effector, enhances HIV-1 virion production by modulating exocytosis.

Overexpression of ROCK in human breast cancer cells: evidence that ROCK activity mediates intracellular membrane traffic of lysosomes.

Small guanosine triphosphatase Rho/Rho-associated kinase as a novel regulator of intracellular redistribution of lysosomes in invasive tumor cells.

Endogenously expressed HIV-1 nef down-regulates antigen-presenting molecules, not only class I MHC but also CD1a, in immature dendritic cells.

Endocytosis in viral replication.

The downregulation of CD4 and MHC-I by primate lentiviruses: a paradigm for the modulation of cell surface receptors.

Ion transport across transmembrane pores.
Endocytosis movies
YouTube Endo- and Exocytosis movies
Endo- and Exocytosis prof. Toid

H+ extrusion from the cytoplasm depends on 2 pumps:

Acidification of endosome - Reactome;

Na+/H+ antiport

The stoichiometry at the level of the membrane complex (Band3, GAPDH, Na+/H+ antiport, Iron reducing electrons carrier) is

  • 1 phosphate uptake
  • 1 NAD+ --> NADH + H+
  • 1 NADH + H+ is then oxidized to NAD+
    • 2 H+ are exchanged with 2 Na+
    • 2 e- are translocated to reduce 2 Fe+++ to Fe++ which enter the cell

As an example into erythrocytes Hb (4 Fe++) and DPG (2 Phosphate) are equimolar (around 5 mM) and the ratio Pin/Fe is 0,5 as expected in a cell in which the phosphate is not used for proliferation (DNA synthesis)

The sodium/hydrogen exchanger: A possible mediator of immunity 2006

Insulin activation of red blood cell Na+/H+ exchange decreases the affinity of sodium sites.

Protons gradient can be used to fuel many type of movement......

In both cases protons efflux requires ATP breakdown (directly or through a Na+ gradient created by Na+/K+ATPase)

Endocytosis is associated with cell movement

Factors involved in cell movement:

  • Adhesion molecules
  • Integrins
  • Microfilaments and microtubules
  • Proteins of RhoA family
  • Proton sources

Drugs affecting acidity of acid vacuoles

Omeprazole and PTH

more info ....

Additional material

Dubinsky model


MHC class I

MCH class II

2010-10-01T12:39:58 - Gianpiero Pescarmona

Late endosomes migrano alla periferia se fuori pH 6.5 serini guido

GAPDH mia.gifgp01/05/2007
Omeprazole PTH.docgp19/04/2007
movement copia.gifgp19/04/2007
GAPDH 700.gifgp17/04/2007
acidic vesicles pH.jpggp04/04/2007
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