Mutant/mutation
For tetracyclin (ATc)-dependent gene regulation the hsp101 locus was mutated using construct pPRF-TRAD4-Tet07-HAPRFhDHFR (RMgm-797) for introducing a tet-inducible promoter and TRAD4 activating domain

Protein (function)
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.
The unsuccessful attempts to disrupt the hsp101 gene (RMgm-914, RMgm-945) indicate an essential role of HSP101 in blood stages.

Phenotype
HSP101 expression in Pbi101KD blood stages was downregulated by addition of the tetracycline derivative anhydrotetracycline (ATc). Strongly reduced growth (parasitemia) in mice treated with ATc. Evidence is presented that treated parasites are able to invade and develop into ring forms but are affected in the development of trophozoite and schizont stage. Evidence is presented that export of proteins into the host RBC is affected in ATc-treated Pbi101KD blood stages.

Additional information
To examine the growth effect in more detail, purified ring-stagePbi101 KD parasites were injected into mice pre-exposed to ATc, then isolated 29 h later and cultured in vitro with ATc. Parasites invaded erythrocytes in the mice and developed normally into ring stages. However, parasites appeared morphologically abnormal by the 34 h time point and were incapable of developing into schizonts by the 46 h time point, unlike Pbi101KD parasites not exposed to ATc. Asynchronous Pbi101KD ring-stage parasites cultured in vitro for 16 hin the presence ofATc demonstrated a threefold to sixfold decrease in hsp101 messenger RNA in schizont stages and a 85–90% knockdown of HSP101 protein by the 29 h time point.

Other mutants