Related Experiment Video
Updated: Jun 18, 2026

Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei
Published on: January 22, 2019
An isoform of the vacuolar (H(+))-ATPase accessory subunit Ac45
Eric J R Jansen1, Nick H M van Bakel, Anthon J M Coenen
1Donders Institute for Brain, Cognition and Behaviour, and Nijmegen Centre for Molecular Life Sciences (NCMLS), Department of Molecular Animal Physiology, Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands.
Abstract:
The vacuolar (H(+))-ATPase (V-ATPase) is the main regulator of intraorganellar pH and in neuroendocrine cells is controlled by its accessory subunit, Ac45. Here, we report the discovery of the first isoform of a V-ATPase accessory subunit, namely an Ac45-like protein, denoted Ac45LP. Phylogenetic analysis revealed a lineage-dependent evolutionary history: Ac45 is absent in birds, and Ac45LP is absent in placental mammals, whereas all other tetrapod species contain both genes. In contrast to Ac45, Ac45LP is not proteolytically cleaved, a prerequisite for proper Ac45 routing. Intriguingly, Xenopus Ac45LP mRNA was expressed in developing neural tissue and in neural crest cells. In adult Xenopus, Ac45 mRNA is widely expressed mostly in neuroendocrine tissues, while Ac45LP mRNA expression was found to be restricted to the kidney and the lung. This novel Ac45LP may provide additional possibilities for V-ATPase regulation during neurodevelopment as well as in kidney and lung cells.
Related Concept Videos
ATP Driven Pumps III: V-type Pumps
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The ADP/ATP Carrier Protein
ATP Driven Pumps II: P-type Pumps
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
ATP Synthase: Structure
Intralumenal Vesicles and Multivesicular Bodies
ATP Synthase: Mechanism

