次黃嘌呤-鳥嘌呤磷酸核苷轉移酶

HGPRT催化下列反應：

HGPRTase functions primarily to salvage purines from degraded DNA to reintroduce into purine synthetic pathways. In this role, it catalyzes the reaction between guanine and phosphoribosyl pyrophosphate (PRPP) to form GMP, or between hypoxanthine and phosphoribosyl pyrophosphate (PRPP) to form inosine monophosphate.

Comparative homology modelling of this enzyme in L. donovani suggest that among all of the computationally screened compounds, pentamidine, 1,3-dinitroadamantane, acyclovir and analogs of acyclovir had higher binding affinities than the real substrate (guanosine monophosphate).[3]

此基因的突變往往導致高尿酸血症：

• 一些男性帶有部分程度的HGPRT缺陷（約低於正常活動量20%）並因此導致血液中高濃度的尿酸。隨之而來的是痛風以及腎結石。這症狀稱為凱利-塞米勒症候群。[4]
• 萊希-尼亨症候群起源由HPRT1突變導致的HGPRT缺陷。[5]
• 某些基因突變可能導致痛風。發病的風險與hypoxanthine-guanine phosphoribosyltransferase的缺陷程度成正比。

• HPRT expression on the mRNA and protein level is induced by hypoxia inducible factor 1 (HIF1A). HIF-1 is a transcription factor that directs an array of cellular responses that are used for adaptation during oxygen deprivation. This finding implies that HPRT is a critical pathway that helps preserve the cell's purine nucleotide resources under hypoxic conditions as found in pathology such as myocardial ischemia.[6]

The in silico and in-vitro correlation of these compounds were test in Leishmania HGPRT and validates the result.[7]

Hybridomas are immortal (immune to cellular senescence), HGPRT⁺ cells that result from fusion of mortal, HGPRT⁺ plasma cells and immortal, HGPRT⁻ myeloma cells. They are created to produce monoclonal antibodies in biotechnology. HAT medium inhibits de novo synthesis of nucleic acids, killing myeloma cells that cannot switch over to the salvage pathway, due to lack of HRPT1. The plasma cells in the culture eventually die from senesence, leaving pure hybridoma cells.

• MeSH（醫學主題詞）上面的Hypoxanthine+phosphoribosyltransferase（美式英语）
• Purine metabolism at genome.jp
• GeneReviews/NCBI/NIH/UW entry on Lesch-Nyhan Syndrome

Category:EC 2.4.2