@article{fdi:010066849,
  title = {{C}haracterization of an {A}-kinase anchoring protein-like suggests an alternative way of {PKA} anchoring in {P}lasmodium falciparum},
  author = {{B}andje, {K}. and {N}aissant, {B}. and {B}igey, {P}. and {L}ohezic, {M}. and {V}ayssieres, {M}. and {B}laud, {M}. and {K}ermasson, {L}. and {L}opez-{R}ubio, {J}. {J}. and {L}angsley, {G}. and {L}avazec, {C}. and {D}eloron, {P}hilippe and {M}erckx, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {T}he asexual intra-erythrocytic multiplication of the malaria parasite {P}lasmodium falciparum is regulated by various molecular mechanisms. {I}n eukaryotic cells, protein kinases are known to play key roles in cell cycle regulation and signaling pathways. {T}he activity of c{AMP}-dependent protein kinase ({PKA}) depends on {A}-kinase anchoring proteins ({AKAP}s) through protein interactions. {W}hile several components of the c{AMP} dependent pathway-including the {PKA} catalytic and regulatory subunits-have been characterized in {P}. falciparum, whether {AKAP}s are involved in this pathway remains unclear. {H}ere, {P}f{AKAL}, an open reading frame of a potential {AKAP}-like protein in the {P}. falciparum genome was identified, and its protein partners and putative cellular functions characterized. {M}ethods: {T}he expression of {P}f{AKAL} throughout the erythrocytic cycle of the 3{D}7 strain was assessed by {RT}-q{PCR} and the presence of the corresponding protein by immunofluorescence assays. {I}n order to study physical interactions between {P}f{AKAL} and other proteins, pull down experiments were performed using a recombinant {P}f{AKAL} protein and parasite protein extracts, or with recombinant proteins. {T}hese interactions were also tested by combining biochemical and proteomic approaches. {A}s phosphorylation could be involved in the regulation of protein complexes, both {P}f{AKAL} and {P}f14-3-3{I} phosphorylation was studied using a radiolabel kinase activity assay. {F}inally, to identify a potential function of the protein, {P}f{AKAL} sequence was aligned and structurally modeled, revealing a conserved nucleotide-binding pocket; confirmed by qualitative nucleotide binding experiments. {R}esults: {P}f{AKAL} is the first {AKAP}-like protein in {P}. falciparum to be identified, and shares 23 % sequence identity with the central domain of human {AKAP}18d. {P}f{AKAL} is expressed in mature asexual stages, merozoites and gametocytes. {I}n spite of homology to {AKAP}18, biochemical and immunochemical analyses demonstrated that {P}f{AKAL} does not interact directly with the {P}. falciparum {PKA} regulatory subunit ({P}f{PKA}-{R}), but instead binds and colocalizes with {P}f14-3-3{I}, which in turn interacts with {P}f{PKA}-{R}. {I}n vivo, these different interactions could be regulated by phosphorylation, as {P}f{PKA}-{R} and {P}f14-3-3{I}, but not {P}f{AKAL}, are phosphorylated in vitro by {PKA}. {I}nterestingly, {P}f{AKAL} binds nucleotides such as {AMP} and c{AMP}, suggesting that this protein may be involved in the {AMP}-activated protein kinase ({AMPK}) pathway, or associated with phosphodiesterase activities. {C}onclusion: {P}f{AKAL} is an atypical {AKAP} that shares common features with human {AKAP}18, such as nucleotides binding. {T}he interaction of {P}f{AKAL} with {P}f{PKA}-{R} could be indirectly mediated through a join interaction with {P}f14-3-3{I}. {T}herefore, {P}f{PKA} localization could not depend on {P}f{AKAL}, but rather involves other partners.},
  keywords = {{A}-kinase anchoring protein like ({AKAL}) ; 14-3-3 protein ; {P}lasmodium falciparum ; {AMP} ; {I}nteractome ; {N}ucleotide},
  booktitle = {},
  journal = {{M}alaria {J}ournal},
  volume = {15},
  numero = {},
  pages = {art. 248 [13 p.]},
  ISSN = {1475-2875},
  year = {2016},
  DOI = {10.1186/s12936-016-1275-9},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066849},
}