Sulfate activation and transport in mammals: system components and mechanisms.

Journal Article (Review)

Extensive studies on the mammalian sulfate-activating enzymes and PAPS translocase have enhanced our understanding of the overall pathway of sulfate activation and utilization. Isolation of the PAPS-synthesizing activities from rat chondrosarcoma and preparation of stable non-hydrolyzable analogs of APS and PAPS have facilitated the kinetic characterization of mammalian ATP sulfurylase and APS kinase. These studies provided the basis for further experimental work showing that APS, the labile intermediate product, is channeled directly between the sulfurylase and kinase active sites. The defect in the brachymorphic mutant mouse lies in this channeling mechanism, thus interfering with efficient PAPS production. The rat chondrosarcoma ATP sulfurylase and APS kinase activities, in fact, reside in a single bifunctional cytoplasmic protein, which has now been cloned and expressed. The mechanism by which PAPS reaches its sites of utilization in the Golgi lumen has also been elucidated: The PAPS translocase is a 230-kDa integral Golgi membrane protein which functions as an antiport.

Full Text

Duke Authors

Cited Authors

  • Schwartz, NB; Lyle, S; Ozeran, JD; Li, H; Deyrup, A; Ng, K; Westley, J

Published Date

  • February 1998

Published In

Volume / Issue

  • 109 / 1-3

Start / End Page

  • 143 - 151

PubMed ID

  • 9566742

Electronic International Standard Serial Number (EISSN)

  • 1872-7786

International Standard Serial Number (ISSN)

  • 0009-2797

Digital Object Identifier (DOI)

  • 10.1016/s0009-2797(97)00129-4

Language

  • eng