Additional remarks phenotype | Mutant/mutation
From the first paper (PMID: 28481199):
The mutant lacks expression of SOC6 and expresses RFP and GFP in female and male gametocytes, respectively. The mutant has not been cloned and analysed in detail. The uncloned population showed normal gametocyte production and exflagellation (male gamete formation).
See below for details of the phenotype of a (cloned?) mutant line lacking expression of SOC6 in the second paper (PMID: 30315162)
Protein (function)
The protein is identified in a screen for proteins that are phosphorylated by CDPK4.CDPK4 has an essential role in male (micro)gamete formation (exflagellation).
Among these proteins, it was decided to name those without predicted function SOC, for substrate of CDPK4. Ten proteins were indeed conserved Plasmodium proteins of unknown function and one protein, SOC2, was annotated as cyclin-related protein 2 but it was suggested be unrelated to cyclins. Also GAP40 was identified.
To investigate the roles of SOC1 to 4 and GAP40 during gametogenesis, it was attempted to individually knock-out their encoding proteins. As controls, soc5 and soc6 were included that were not differentially phosphorylated in a CDPK4-KO mutant. For gap40 no transgenic parasites could be obtained. Viable KO parasites could be detected in mixed asexual stages for six genes and non-clonal populations were first assessed for microgametocyte DNA replication and exflagellation. No defects were observed in the SOC4-KO line as well as in the SOC5-KO and SOC6-KO control lines suggesting that these proteins do not represent crucial CDPK4 effectors in the regulation of male gametogenesis. Defects in DNA replication or exflagellation were observed for SOC1-KO, SOC2-KO, and SOC3-KO lines that were cloned for in depth characterisation.
Phenotype
From the first paper (PMID: 28481199):
The mutant lacks expression of SOC6 and expresses RFP and GFP in female and male gametocytes, respectively. The mutant has not been cloned and analysed in detail. The uncloned population showed normal gametocyte production and exflagellation (male gamete formation).
From the second paper (PMID: 30315162)
'A SOC6-KO line shows a significant growth defect compared with wild type. While segmented SOC6-KO schizonts display the same number of merozoites as wild type, they show a reduced capacity to transform into ring stage parasites, while no accumulation of circulating SOC6-KO schizonts is observed. This indicates SOC6 is important either at the final stage of schizont maturation or to invade new RBCs. TEM of purified SOC6-KO schizonts reveals a discontinuous IMC as observed for PKGT619Q-3xHA/CDPK4-KO transgenic, suggesting that SOC6 is important for the formation or the stability of the IMC in merozoites. To investigate the function of SOC6 further, we turned to the ookinete stage, which in P. berghei offers a tractable model to study the molecular motor that powers gliding motility. Ookinetes emerge from the zygote that forms after fertilisation of macrogametes by microgametes in the mosquito blood meal. Male gamete formation does not require SOC6, but the SOC6-KO nevertheless fails to form typical banana-shaped ookinetes. Again, TEM of SOC6-KO cells reveals either a discontinuous IMC or the complete absence of an IMC below the plasma membrane, suggesting that SOC6 plays a conserved role to control the IMC formation or stability at multiple stages of the malaria lifecycle.'
Additional information
Other mutants |