title: Experimentally controlled downregulation of the histone chaperone FACT in Plasmodium berghei reveals that it is critical to male gamete fertility.
abstract: Human FACT (facilitates chromatin transcription) consists of the proteins SPT16 and SSRP1 and acts as a histone chaperone in the (dis)assembly of nucleosome (and thereby chromatin) structure during transcription and DNA replication. We identified a Plasmodium berghei protein, termed FACT-L, with homology to the SPT16 subunit of FACT. Epitope tagging of FACT-L showed nuclear localization with high expression in the nuclei of (activated) male gametocytes. The gene encoding FACT-L could not be deleted indicating an essential role during blood-stage development. Using a 'promoter-swap' approach whereby the fact-l promoter was replaced by an 'asexual blood stage-specific' promoter that is silent in gametocytes, transcription of fact-l in promoter-swap mutant gametocytes was downregulated compared with wild-type gametocytes. These mutant male gametocytes showed delayed DNA replication and gamete formation. Male gamete fertility was strongly reduced while female gamete fertility was unaffected; residual ookinetes generated oocysts that arrested early in development and failed to enter sporogony. Therefore FACT is critically involved in the formation of fertile male gametes and parasite transmission. 'Promoter swapping' is a powerful approach for the functional analysis of proteins in gametocytes (and beyond) that are essential during asexual blood-stage development.
authors: Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical, Albinusdreef 2, 2333 ZA Leiden, the Netherlands.
authors: Eliane C
authors: EC
authors: Laurentino
authors: Sonya
authors: S
authors: Taylor
authors: Gunnar R
authors: GR
authors: Mair
authors: Edwin
authors: E
authors: Lasonder
authors: Richard
authors: R
authors: Bartfai
authors: Hendrik G
authors: HG
authors: Stunnenberg
authors: Hans
authors: H
authors: Kroeze
authors: Jai
authors: J
authors: Ramesar
authors: Blandine
authors: B
authors: Franke-Fayard
authors: Shahid M
authors: SM
authors: Khan
authors: Chris J
authors: CJ
authors: Janse
authors: Andrew P
authors: AP
authors: Waters
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology; D002467:Cell Nucleus / Q000378:metabolism; D004261:DNA Replication; D016054:DNA, Protozoan / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D018604:Epitope Mapping; D005260:Female; D005298:Fertility; D005407:Flagella / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D005854:Germ Cells / Q000378:metabolism / Q000502:physiology*; D056488:Histone Chaperones / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D033661:Oocysts / Q000378:metabolism / Q000502:physiology; D010962:Plasmodium berghei / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D016054:DNA, Protozoan; D004268:DNA-Binding Proteins; D056488:Histone Chaperones; D015800:Protozoan Proteins