ATP- and Gap Junction–dependent Intercellular Calcium Signaling in Osteoblastic Cells

• DOI: 10.1083/jcb.139.2.497
• Publication Date: 2002-07-26T16:47:50Z
• Authors: Niklas R. Jørgensen; Steven T. Geist; Roberto Civitelli; Thomas H. Steinberg
• Keywords: Calcium in biology; Calcium Signaling

Many cells coordinate their activities by transmitting rises in intracellular calcium from cell to cell. In nonexcitable cells, there are currently two models for intercellular wave propagation, both of which involve release inositol trisphosphate (IP3)- sensitive stores. one model, IP3 traverses gap junctions and initiates the stores neighboring cells. Alternatively, waves may be mediated not junctional communication, but rather autocrine activity secreted ATP on P2 purinergic receptors. We studied mechanically induced rat osteosarcoma lines that differ junction proteins they express, ability pass microinjected dye cell, expression P2Y2 (P2U) ROS 17/2.8 express protein connexin43 (Cx43), well coupled, lack P2U receptors, transmitted slow junction-dependent did require UMR 106-01 predominantly connexin 45 (Cx45), poorly receptors; propagated fast required activation communication. ROS/P2U transfectants UMR/Cx43 expressed types waves. Gap junction–independent, ATP-dependent were also seen hamster tracheal epithelia These studies demonstrate receptors can propagate calcium, describe a novel Cx43-dependent mechanism propagation does IP3. suggest communication either Cx43 or Cx45 allow passage enough elicit