TY - JOUR
T1 - Involvement of plasmodium falciparum protein kinase CK2 in the chromatin assembly pathway
AU - Dastidar, Eeshita G
AU - Dayer, Guillem
AU - Holland, Zoe M
AU - Dorin-Semblat, Dominique
AU - Claes, Aurelie
AU - Chene, Arnaud
AU - Sharma, Amit
AU - Hamelin, Romain
AU - Moniatte, Marc
AU - Lopez-Rubio, Jose-Juan
AU - Scherf, Artur
AU - Doerig, Christian D
PY - 2012
Y1 - 2012
N2 - BACKGROUND: Protein kinase CK2 is a pleiotropic serine/threonine protein kinase with hundreds of reported substrates, and plays an important role in a number of cellular processes. The cellular functions of Plasmodium falciparum CK2 (PfCK2) are unknown. The parasite s genome encodes one catalytic subunit, PfCK2alpha, which we have previously shown to be essential for completion of the asexual erythrocytic cycle, and two putative regulatory subunits, PfCK2beta1 and PfCK2beta2. RESULTS: We now show that the genes encoding both regulatory PfCK2 subunits (PfCK2beta1 and PfCK2beta2) cannot be disrupted. Using immunofluorescence and electron microscopy, we examined the intra-erythrocytic stages of transgenic parasite lines expressing hemagglutinin (HA)-tagged catalytic and regulatory subunits (HA-CK2alpha, HA-PfCK2beta1 or HA-PfCK2beta2), and localized all three subunits to both cytoplasmic and nuclear compartments of the parasite. The same transgenic parasite lines were used to purify PfCK2beta1- and PfCK2beta2-containing complexes, which were analyzed by mass spectrometry. The recovered proteins were unevenly distributed between various pathways, with a large proportion of components of the chromatin assembly pathway being present in both PfCK2beta1 and PfCK2beta2 precipitates, implicating PfCK2 in chromatin dynamics. We also found that chromatin-related substrates such as nucleosome assembly proteins (Naps), histones, and two members of the Alba family are phosphorylated by PfCK2alpha in vitro. CONCLUSIONS: Our reverse-genetics data show that each of the two regulatory PfCK2 subunits is required for completion of the asexual erythrocytic cycle. Our interactome study points to an implication of PfCK2 in many cellular pathways, with chromatin dynamics being identified as a major process regulated by PfCK2. This study paves the way for a kinome-wide interactomics-based approach to elucidate protein kinase function in malaria parasites.
AB - BACKGROUND: Protein kinase CK2 is a pleiotropic serine/threonine protein kinase with hundreds of reported substrates, and plays an important role in a number of cellular processes. The cellular functions of Plasmodium falciparum CK2 (PfCK2) are unknown. The parasite s genome encodes one catalytic subunit, PfCK2alpha, which we have previously shown to be essential for completion of the asexual erythrocytic cycle, and two putative regulatory subunits, PfCK2beta1 and PfCK2beta2. RESULTS: We now show that the genes encoding both regulatory PfCK2 subunits (PfCK2beta1 and PfCK2beta2) cannot be disrupted. Using immunofluorescence and electron microscopy, we examined the intra-erythrocytic stages of transgenic parasite lines expressing hemagglutinin (HA)-tagged catalytic and regulatory subunits (HA-CK2alpha, HA-PfCK2beta1 or HA-PfCK2beta2), and localized all three subunits to both cytoplasmic and nuclear compartments of the parasite. The same transgenic parasite lines were used to purify PfCK2beta1- and PfCK2beta2-containing complexes, which were analyzed by mass spectrometry. The recovered proteins were unevenly distributed between various pathways, with a large proportion of components of the chromatin assembly pathway being present in both PfCK2beta1 and PfCK2beta2 precipitates, implicating PfCK2 in chromatin dynamics. We also found that chromatin-related substrates such as nucleosome assembly proteins (Naps), histones, and two members of the Alba family are phosphorylated by PfCK2alpha in vitro. CONCLUSIONS: Our reverse-genetics data show that each of the two regulatory PfCK2 subunits is required for completion of the asexual erythrocytic cycle. Our interactome study points to an implication of PfCK2 in many cellular pathways, with chromatin dynamics being identified as a major process regulated by PfCK2. This study paves the way for a kinome-wide interactomics-based approach to elucidate protein kinase function in malaria parasites.
UR - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=22293287
U2 - 10.1186/1741-7007-10-5
DO - 10.1186/1741-7007-10-5
M3 - Article
SN - 1741-7007
VL - 10
SP - 1
EP - 16
JO - BMC Biology
JF - BMC Biology
IS - 5
ER -
