Details

Autor(en) / Beteiligte

• Kim, J.C., Chungnam National University, Daejeon, Republic of Korea
• Son, M.J., Chungnam National University, Daejeon, Republic of Korea
• Subedi, Krishna P., Chungnam National University, Daejeon, Republic of Korea
• Kim, D.H., Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
• Woo, S.H., Chungnam National University, Daejeon, Republic of Korea

Titel

IP₃-induced cytosolic and nuclear Ca²+ signals in HL-1 atrial myocytes: Possible role of IP₃ receptor subtypes

Ist Teil von

• Molecules and Cells, 2010, 29(4), , pp.387-395

Ort / Verlag

Springer: Korean Society for Molecular and Cellular Biology

Erscheinungsjahr

2010

Quelle

MEDLINE

Beschreibungen/Notizen

• HL-1 cells are the adult cardiac cell lines available that continuously divide while maintaining an atrial phenotype. Here we examined the expression and localization of inositol 1,4,5-trisphosphate receptor (IP₃R) subtypes, and investigated how pattern of IP₃-induced subcellular local Ca²+ signaling is encoded by multiple IP₃R subtypes in HL-1 cells. The type 1 IP₃R (IP₃R1) was expressed in the perinucleus with a diffuse pattern and the type 2 IP₃R (IP₃R2) was expressed in the cytosol with a punctate distribution. Extracellular ATP (1 mM) elicited transient intracellular Ca²+ releases accompanied by a Ca²+ oscillation, which was eliminated by the blocker of IP₃Rs, 2-APB, and attenuated by ryanodine. Direct introduction of IP₃ into the permeabilized cells induced Ca²+ transients with Ca²+ oscillations at greater-than or equal to 20 μM of IP₃, which was removed by the inhibition of IP₃Rs using 2-APB and heparin. IP₃-induced local Ca²+ transients contained two distinct time courses: a rapid oscillation and a monophasic Ca²+ transient. The magnitude of Ca²+ oscillation was significantly larger in the cytosol than in the nucleus, while the monophasic Ca²+ transient was more pronounced in the nucleus. These results provide evidence for the molecular and functional expression of IP₃R1 and IP₃R2 in HL-1 cells, and suggest that such distinct local Ca²+ signaling may be correlated with the punctate distribution of IP₃R2s in the cytosol and the diffuse localization of IP₃R1 in the peri-nucleus.