Oligomerization of the plasma membrane calcium pump involves two regions with different thermal stability

Ca2+ pump dimerization was studied by using a combined approach of thermal denaturation and fluorescence resonance energy transfer. The measurement of calcium pump ability to dimerize after the unfolding of individual functio nal domains of the enzyme demonstrated the existence of two different regio ns involved in the self-association process. One of these regions is highly susceptible to thermal unfolding and was identified as the calmodulin (CaM )-binding domain, The other region whose thermal stability is higher than t hose of the catalytic and CaM-binding domains could be related with the pre viously found C28W-binding regions, (C) 2000 Federation of European Biochem ical Societies, Published by Elsevier Science B.V. All rights reserved.