Mutant/mutation
The mutant lacks expression of TRX2.

Protein (function)
Thioredoxins act as both reducing agents and protein disulfide reductases.
P. falciparum contains three thioredoxins - Trx1, Trx2, Trx3 and two thioredoxin-like proteins (Tlp1 and Tlp2). Trx1 and Tlp1 are cytosolic, Trx3 is localized to the endoplasmic reticulum, while Tlp2 is mitochondrial. Thioredoxin 2 is a 19 kDa protein with an ER signal sequence and is part of the so-called translocon complex (PTEX) which is a parasite derived multi-protein machinery resident in parasite parasitophorous vacuolar membrane (PVM), responsible for protein secretion into host cells
Plasmodium parasites remodel their vertebrate host cells by translocating hundreds of proteins across an encasing membrane into the host cell cytosol via a putative export machinery termed PTEX (Plasmodium Translocon of EXported protein). HSP101 (PbANKA_094120), PTEX150 (PbANKA_100850), EXP2 (PbANKA_133430), PTEX88 (PbANKA_094130) and TRX2 (PbANKA_135800) have been identified as members of the PTEX complex.
These proteins are also expressed  in early gametocytes, mosquito and liver stages. Although amenable to genetic tagging, HSP101, PTEX150, EXP2 and PTEX88 could not be genetically deleted in P. berghei, in keeping with the obligatory role this complex is postulated to have in maintaining normal blood-stage growth. In contrast, the putative thioredoxin-like protein TRX2 could be deleted, with knockout parasites displaying reduced grow-rates, both in vivo and in vitro.

Phenotype
Blood stages show a delayed growth in mice. Evidence is presented for a prolonged cell cycle of asexual blood stages, mainly affecting the development of ring forms and schizonts. The number of merozoites per schizont was comparable to that of wild type schizonts.

Additional information
Infections with the mutant parasite do not induce experimental cerebral malaria (ECM) in C57Bl6 mice.

Other mutants