Regulation of thioredoxin reductase by calcium in Hermansky-Pudlak syndrome

✍ Scribed by K. U. Schallreuter; M. R. Pittelkow

• Book ID: 104769664
• Publisher: Springer-Verlag
• Year: 1989
• Tongue: English
• Weight: 480 KB
• Volume: 281
• Category: Article
• ISSN: 0340-3696
• DOI: 10.1007/bf00424271

✦ Synopsis

Cell cultures of keratinocytes, established from four Hermansky-Pndlak syndrome (HPS) homozygotes yielded low membrane-associated thioredoxin reductase activities compared with normal healthy adult controls. This low activity has been shown to be caused by a special sensitivity of the enzyme to calcium. 4SCalcium has been used to compare the kinetics for the transport and bioaccumulation of this regulatory cation in keratinocyte cultures of a kindred with HPS (i.e., one HPS homozygote, one HPS obligate heterozygote, one normal family member, and healthy adult controls). The results show that both HPS-homozygous and -heterozygous cells bind more extracellular calcium than noncarriers of this genetic defect, and HPS homozygous cells appear to have a defective calcium transport system.