Mutant/mutation
The mutant lacks expression of PTPLA and expresses GFP under the constitutive eef1a promoter.

Protein (function)
The gene was targetted for deletion/tagging in a systematic functional analysis of the entire P. berghei protein phosphatome, which comprises 30 predicted protein phosphatases (PPs), that exhibit differential and distinct expression patterns during various stages of the life-cycle. Gene disruption analysis of all P. berghei PPs revealed that half of the genes are likely essential for asexual blood stage development; whereas six are essential for sexual development/sporogony in the mosquito.
The parasite utilises a number of signal transduction mechanisms, including reversible protein phosphorylation catalysed by protein kinases (PKs) and phosphatases (PPs). This mechanism of signalling is a conserved, ubiquitous regulatory process for many eukaryotic and prokaryotic cellular pathways.

Sequence analysis of the P. falciparum parasite has revealed approximately 85 putative PK and 27 putative PP catalytic subunits encoded in its genome (the Plasmodium protein phosphatome being one of the smallest of the eukaryotic phyla).
The Plasmodium phosphatome has been classified into 4 major groups: phosphoprotein phosphatases (PPPs), metallo-dependent protein phosphatases (PPMs), protein tyrosine phosphatases (PTPs) and NLI interacting factor-like phosphatases (NIFs), as well as a number of smaller classes.

To define the phosphatome, PPs encoded in the genomes of P. berghei and P. falciparum were identified by similarity to hidden Markov models of known PP catalytic domains. PFam domains were used to define protein sets with similarity to PPP, PTP, PPM, NIF-like and PTP-like A families. There are no predicted PPs with good similarity to the Low-Molecular Weight Phosphatase (LMWP) or CDC25 families. There are also no good matches to models of SSU72 RNA polymerase II CTD phosphatase or Eyes Absent (EYA) phosphatase. Other PFam domains specific to PP catalytic domains are subclasses of the above families. The 5 identified Plasmodium PP families were compared to 4969 PP-like proteins from 44 diverse eukaryotes, to classify them and eliminate PP-like proteins with confirmed non-protein phosphatase functions.

In this study 30 and 29 PPs were identified in the genomes of P. berghei and P. falciparum respectively, encompassing 28 direct orthologues across the 5 PP families described above.
As found with the kinome, the phosphatome is highly conserved with only three proteins without direct orthology between P. falciparum and P. berghei.
On the basis of catalytic domain phylogeny and domain architecture, the Plasmodium PPPtype phosphatases can be further classified into subfamilies, with PPP1 to PPP7 corresponding to the animal PP1-PP7 types. Plasmodium PPPs also include the BSU-like phosphatase PPKL, an EF-hand containing phosphatase (EFPP) and the two SHLPs, none of which is present in the host.

Phenotype
Normal oocyst size and numbers. No sporozoites formed 14 or 21 days post-infection

Additional information

Other mutants