Mammalian and Malaria Parasite Cyclase-associated Proteins Catalyze Nucleotide Exchange on G-actin through a Conserved Mechanism
| Autor: | Maarit Makkonen, Pekka Lappalainen, Natalia A. Chebotareva, Enni Bertling, Jake Baum |
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| Rok vydání: | 2013 |
| Předmět: |
Plasmodium
Molecular Sequence Data macromolecular substances environment and public health Biochemistry Catalysis 03 medical and health sciences chemistry.chemical_compound Adenosine Triphosphate Biopolymers Animals Nucleotide Amino Acid Sequence Actin-binding protein Cytoskeleton Molecular Biology Actin 030304 developmental biology Cyclase-associated protein family chemistry.chemical_classification 0303 health sciences Sequence Homology Amino Acid biology 030302 biochemistry & molecular biology Cell Biology Cofilin Actins 3. Good health chemistry Profilin biology.protein Electrophoresis Polyacrylamide Gel Rabbits Carrier Proteins Adenosine triphosphate |
| Zdroj: | Journal of Biological Chemistry. 288:984-994 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m112.435719 |
| Popis: | Cyclase-associated proteins (CAPs) are among the most highly conserved regulators of actin dynamics, being present in organisms from mammals to apicomplexan parasites. Yeast, plant, and mammalian CAPs are large multidomain proteins, which catalyze nucleotide exchange on actin monomers from ADP to ATP and recycle actin monomers from actin-depolymerizing factor (ADF)/cofilin for new rounds of filament assembly. However, the mechanism by which CAPs promote nucleotide exchange is not known. Furthermore, how apicomplexan CAPs, which lack many domains present in yeast and mammalian CAPs, contribute to actin dynamics is not understood. We show that, like yeast Srv2/CAP, mouse CAP1 interacts with ADF/cofilin and ADP-G-actin through its N-terminal α-helical and C-terminal β-strand domains, respectively. However, in the variation to yeast Srv2/CAP, mouse CAP1 has two adjacent profilin-binding sites, and it interacts with ATP-actin monomers with high affinity through its WH2 domain. Importantly, we revealed that the C-terminal β-sheet domain of mouse CAP1 is essential and sufficient for catalyzing nucleotide exchange on actin monomers, although the adjacent WH2 domain is not required for this function. Supporting these data, we show that the malaria parasite Plasmodium falciparum CAP, which is entirely composed of the β-sheet domain, efficiently promotes nucleotide exchange on actin monomers. Collectively, this study provides evidence that catalyzing nucleotide exchange on actin monomers via the β-sheet domain is the most highly conserved function of CAPs from mammals to apicomplexan parasites. Other functions, including interactions with profilin and ADF/cofilin, evolved in more complex organisms to adjust the specific role of CAPs in actin dynamics. |
| Databáze: | OpenAIRE |
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