Functional characterisation of the actin-depolymerising factor from the apicomplexan Neospora caninum (NcADF)

Author(s)

Baroni, Luciana ^[1] ; Pereira, Luiz M. ^[1] ; Maciver, Sutherland K. ^[2] ; Yatsuda, Ana P. ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Av Cafe S-N, BR-14040930 Ribeirao Preto, SP - Brazil

^[2] Univ Edinburgh, Edinburgh Med Sch, Ctr Discovery Brain Sci, Biomed Sci, Hugh Robson Bldg, George Sq, Edinburgh EH8 9XD, Midlothian - Scotland

• Document type: Journal article
• Source: Molecular and Biochemical Parasitology; v. 224, p. 26-36, SEP 15 2018.
• Web of Science Citations: 0

Abstract

Neospora caninum is an apicomplexan parasite that causes infectious abortion in cows. As an obligate intracellular parasite, N. caninum requires a host cell environment to survive and replicate. The locomotion and invasion mechanisms of apicomplexan parasites are centred on the actin-myosin system to propel the parasite forwards and into the host cell. The functions of actin, an intrinsically dynamic protein, are modulated by actinbinding proteins (ABPs). Actin-depolymerising factor (ADF) is a ubiquitous ABP responsible for accelerating actin turnover in eukaryotic cells and is one of the few known conserved ABPs from apicomplexan parasites. Apicomplexan ADFs have nonconventional properties compared with ADF/cofilins from higher eukaryotes. In the present paper, we characterised the ADF from N. caninum (NcADF) using computational and in vitro biochemical approaches to investigate its function in rabbit muscle actin dynamics. Our predicted computational tertiary structure of NcADF demonstrated a conserved structure and phylogeny with respect to other ADF/cofilins, although certain differences in filamentous actin (F-actin) binding sites were present. The activity of recombinant NcADF on heterologous actin was regulated in part by pH and the presence of inorganic phosphate. In addition, our data suggest a comparatively weak disassembly of F-actin by NcADF. Taken together, the data presented herein represent a contribution to the field towards the understanding of the role of ADF in N. caninum and a comparative analysis of ABPs in the phylum Apicomplexa. (AU)

• FAPESP's process: 15/04258-8 - Actin-binding proteins (ABPs) from Neospora caninum: role of actin-depolymerizing factor (NcADF) and cyclase-associated protein (NcCAP) in actin dynamics
• Grantee: Luciana Baroni
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/22772-2 - Identification and characterization of actin-binding proteins (ABPs) of the Apicomplexan parasite Neospora caninum
• Grantee: Luciana Baroni
• Support Opportunities: Scholarships in Brazil - Doctorate