Regulatory role of E-NTPase/E-NTPDase in Ca2+/Mg2+ transport via gated channel.
BACKGROUND
E-NTPase/E-NTPDase is activated by millimolar concentrations of Ca2+ or Mg2+ with a pH optimum of 7.5 for the hydrolysis of extracellular NTP and NDP. It has been generally accepted that E-NTPase/E-NTPDase plays regulatory role in purinergic signalling, but other functions may yet be discovered.


RESULTS
In this article it is proposed on the basis of published data that E-NTPase/E-NTPDase could play a role in the influx and efflux of Ca2+and Mg2+ in vivo.


CONCLUSIONS
Attenuation of extracellular Ca2+ influx by rat cardiac sarcoplasmic anti-E-NTPase antibodies and oligomerization studies on mammalian CD39 conclusively point towards the existence of a new channel in the membrane. Further studies on these properties of the E-NTPase/E-NTPDase may provide detailed mechanisms and identify the potential patho-physiological significance.
Division of Gastroenterology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. skannan22@hotmail.com
Hans M
HM
Schreiber
Subburaj
S
Kannan
D000251:Adenosine Triphosphatases / Q000502:physiology*; D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D001081:Apyrase / Q000502:physiology*; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D008274:Magnesium / Q000378:metabolism*; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000201:enzymology
D015703:Antigens, CD; D015220:Calcium Channels; D000251:Adenosine Triphosphatases; C027201:ectoATPase; D001081:Apyrase; C067869:CD39 antigen; D008274:Magnesium; D002118:Calcium