Novel structural and functional findings of the ehFLN protein from Entamoeba histolytica.
The ehFLN protein (previously known as EhABP-120) is the first filamin to be identified in the parasitic protozoan Entamoeba histolytica. Filamins are a family of cross-linking actin-binding proteins that organize filamentous actin in networks and stress fibers. It has been reported that filamins of different organisms directly interact with more than 30 cellular proteins and some PPIs. The biochemical consequences of such interactions may have either positive or negative effects on the cross-linking function. Besides, filamins form a link between cytoskeleton and plasma membrane. In this work, the ehFLN protein was biochemically characterized; amoebae filamin was found to associate with both PA and PI(3)P in vitro, new lipid targets for a member of the filamins. By molecular modeling analysis and protein-lipid overlay assays, K-609, 709, and 710 were determined to be essential for the PA-ehFLN1 complex stability. Also, the integrity of the 4th repeat of ehFLN is essential to keep interaction with the PI(3)P. Transfected trophozoites that overexpressed the d100, d50NH(2), and d50COOH regions of ehFLN1 displayed both increased motility and chemotactic response to TYI-S-33 media. Together, these results suggest that short regions of ehFLN are involved in signaling events that, in cooperation with phosphatidic acid, EhPLD2 and EhPI3K, could promote cell motility.
Díaz-Valencia
Juan Daniel
JD
Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, México, D.F., México.
Almaraz-Barrera
Ma de Jesús
Mde J
Jay
David
D
Hernández-Cuevas
Nora Adriana
NA
García
Elizabeth
E
González-De la Rosa
Claudia H
CH
Arias-Romero
Luis Enrique
LE
Hernandez-Rivas
Rosaura
R
Rojo-Domínguez
Arturo
A
Guillén
Nancy
N
Vargas
Miguel
M
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology; D003285:Contractile Proteins / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism; D004748:Entamoeba histolytica / Q000502:physiology*; D064448:Filamins; D008840:Microfilament Proteins / Q000502:physiology*; D008856:Microscopy, Fluorescence / Q000379:methods; D008958:Models, Molecular; D010712:Phosphatidic Acids / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013433:Sulfoglycosphingolipids / Q000737:chemistry / Q000378:metabolism; D053058:Trophozoites / Q000378:metabolism / Q000469:parasitology / Q000502:physiology
D003285:Contractile Proteins; C431109:EhABPH protein, Entamoeba histolytica; D064448:Filamins; D008840:Microfilament Proteins; D010712:Phosphatidic Acids; D010743:Phospholipids; D015800:Protozoan Proteins; D013433:Sulfoglycosphingolipids