• occurs
  • The fact that both the progesterone receptor (the α1-subunit of the Na/K-ATPase) and PE-NMT are integral membrane enzymes suggests that helix-helix interaction occurs between the M1 and/or M2 transmembrane helix bordering the proposed progesterone binding site [ 3 ] and one or more of the 4 transmembrane helixes of the PE-NMT. (pubmedcentralcanada.ca)
  • cells
  • ATP release colocalized with Panx1 channels in polarized cells, such as airway epithelia, where ATP is secreted exclusively at the air interface ( 4 ), or the apical membrane of kidney epithelial cells ( 6 ). (sciencemag.org)