Dissection of minimal sequence requirements for rhoptry membrane targeting in the malaria parasite

TY - JOUR

T1 - Dissection of minimal sequence requirements for rhoptry membrane targeting in the malaria parasite

AU - Cabrera, Ana

AU - Herrmann, Susann

AU - Warszta, Dominik

AU - Santos, Joana M

AU - John Peter, Arun T

AU - Kono, Maya

AU - Debrouver, Sandra

AU - Jacobs, Thomas

AU - Spielmann, Tobias

AU - Ungermann, Christian

AU - Soldati-Favre, Dominique

AU - Gilberger, Tim W

N1 - © 2012 John Wiley & Sons A/S.

PY - 2012/10/1

Y1 - 2012/10/1

N2 - Rhoptries are specialized secretory organelles characteristic of single cell organisms belonging to the clade Apicomplexa. These organelles play a key role in the invasion process of host cells by accumulating and subsequently secreting an unknown number of proteins mediating host cell entry. Despite their essential role, little is known about their biogenesis, components and targeting determinants. Here, we report on a conserved apicomplexan protein termed Armadillo Repeats-Only (ARO) protein that we localized to the cytosolic face of Plasmodium falciparum and Toxoplasma gondii rhoptries. We show that the first 20 N-terminal amino acids are sufficient for rhoptry membrane targeting. This protein relies on both - myristoylation and palmitoylation motifs - for membrane attachment. Although these lipid modifications are essential, they are not sufficient to direct ARO to the rhoptry membranes. Mutational analysis revealed additional residues within the first 20 amino acids of ARO that play an important role for rhoptry membrane attachment: the positively charged residues R9 and K14. Interestingly, the exchange of R9 with a negative charge entirely abolishes membrane attachment, whereas the exchange of K14 (and to a lesser extent K16) alters only its membrane specificity. Additionally, 17 proteins predicted to be myristoylated and palmitoylated in the first 20 N-terminal amino acids were identified in the genome of the malaria parasite. While most of the corresponding GFP fusion proteins were trafficked to the parasite plasma membrane, two were sorted to the apical organelles. Interestingly, these proteins have a similar motif identified for ARO.

AB - Rhoptries are specialized secretory organelles characteristic of single cell organisms belonging to the clade Apicomplexa. These organelles play a key role in the invasion process of host cells by accumulating and subsequently secreting an unknown number of proteins mediating host cell entry. Despite their essential role, little is known about their biogenesis, components and targeting determinants. Here, we report on a conserved apicomplexan protein termed Armadillo Repeats-Only (ARO) protein that we localized to the cytosolic face of Plasmodium falciparum and Toxoplasma gondii rhoptries. We show that the first 20 N-terminal amino acids are sufficient for rhoptry membrane targeting. This protein relies on both - myristoylation and palmitoylation motifs - for membrane attachment. Although these lipid modifications are essential, they are not sufficient to direct ARO to the rhoptry membranes. Mutational analysis revealed additional residues within the first 20 amino acids of ARO that play an important role for rhoptry membrane attachment: the positively charged residues R9 and K14. Interestingly, the exchange of R9 with a negative charge entirely abolishes membrane attachment, whereas the exchange of K14 (and to a lesser extent K16) alters only its membrane specificity. Additionally, 17 proteins predicted to be myristoylated and palmitoylated in the first 20 N-terminal amino acids were identified in the genome of the malaria parasite. While most of the corresponding GFP fusion proteins were trafficked to the parasite plasma membrane, two were sorted to the apical organelles. Interestingly, these proteins have a similar motif identified for ARO.

KW - Amino Acid Motifs

KW - Amino Acid Sequence

KW - Armadillo Domain Proteins

KW - Cell Membrane

KW - Membrane Proteins

KW - Molecular Sequence Data

KW - Mutation

KW - Organelles

KW - Plasmodium falciparum

KW - Protein Processing, Post-Translational

KW - Protein Transport

KW - Protozoan Proteins

KW - Toxoplasma

U2 - 10.1111/j.1600-0854.2012.01394.x

DO - 10.1111/j.1600-0854.2012.01394.x

M3 - SCORING: Journal article

C2 - 22759070

VL - 13

SP - 1335

EP - 1350

JO - TRAFFIC

JF - TRAFFIC

SN - 1398-9219

IS - 10

ER -