A study of the PfNT3 in Plasmodium falciparum
PfNT3, Plasmodium falciparum Nucleoside permease
Abstract
Previous genetic studies demonstrated that survival and proliferation of Plasmodium falciparum parasites is dependent on salvage of essential purines from the host. Plasmodium falciparum, the causative agent of the most lethal form of human malaria lacks the enzymes required for de novo synthesis of purines. Analysis of the hypothetical nucleoside/nucleobase transporter protein, the gene product of PfNT3 (PF14_0662) gene in P. falciparum parasites was carried out by localisation, in view of a novel chemotherapeutic target. Immunoblotting, immunofluorescent and immunoelectron microscopic localization of PfNT3 was demonstrated using polyclonal antiserum in in vitro cultured Plasmodium falciparum parasites, propagated in human red blood cells. PfNT3 protein, the translated product of PfNT3 gene was detected in intraerythrocytic ring, trophozoite, and schizont stages. PfNT3 was localized primarily to the PPM (Parasite Plasma Membrane). The endogenous PfNT3 putative nucleoside transporter with the predominant location to the parasite plasma membrane may serve not only as routes for targeting of purine analogs/cytotoxic agents into the intracellular parasite but may also serve as drug targets. Being genome encoded the vital transporter protein can be prevented from expression by silencing of the gene, validating it to be a novel drug target.
Keywords :
equilibrative nucleoside transporter,
malaria,
PfNT3 gene,
Plasmodium falciparum,
purines.,
Abstrak
Kajian genetik terdahulu menunjukkan bahawa kelangsungan hidup dan proliferasi parasit Plasmodium falciparum bergantung kepada penggunaan purin utama dalam hos. Plasmodium falciparum, agen penyebab kepada jenis malaria paling merbahaya pada manusia, tidak mempunyai enzim yang diperlukan untuk sintesis purin secara de novo. Berdasarkan kepada sasaran kemoterapeutik yang novel, analisa hipotetikal protein pengangkut nukleosida/nukleobas, hasil dari gen PfNT3 (PF14_0662) dalam parasit P. falciparum, dilakukan secara lokalisasi. Melalui immunobloting, immunoflorescen dan lokalisasi mikroskopik immunoelektron, lokasi PfNT3 didemonstrasi dengan menggunakan anti-serum poliklonal pada kultur in-vitro parasit P. falciparum yang dibiakkan dalam sel darah merah manusia. Protin PfNT3, hasil translasi gen PfNT3, dikesan pada peringkat cincin intraeritrosit, tropozit dan skizon. Tumpuan utama PfNT3 adalah pada membran plasma parasit (MPP). Pengangkut putatif nukleosid endogenous PfNT3 dengan lokasi utama di MPP boleh bertindak bukan sahaja sebagai tapak jalan untuk sasaran analog purin/ agen sitotoksik bagi intraselular parasit , tetapi juga bertindak sebagai sasaran dadah. Sebagai genom terkod, protin pengangkut vital boleh dihalang daripada diekspresi melalui gen ‘silencing’ dan ini mengesahkanya sebagai sasaran dadah yang novel.
Kata Kunci :
gen PfNT3,
malaria,
Pengangkut nukleosida equilibratif,
Plasmodium falciparum,
purin.,
Correspondance Address
Dr. Pratima Kumari Sahu, Biochemistry & Molecular Biology, S. C. B. Medical College, Cuttack-753007, Odisha, India. Tel: 91+671+2313377 Fax: 91+671+2313377 Email: sahupratima@rediffmail.com