Polarity in intracellular calcium signaling

✍ Scribed by Ole H. Petersen; Denis Burdakov; Alexei V. Tepikin

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 138 KB
• Volume: 21
• Category: Article
• ISSN: 0265-9247
• DOI: 10.1002/(sici)1521-1878(199910)21:10<851::aid-bies7>3.0.co;2-f

✦ Synopsis

The concentration of free calcium ions (Ca 2ϩ ) in the cytosol is precisely regulated and can be rapidly increased in response to various types of stimuli. Since Ca 2ϩ can be used to control different processes in the same cell, the spatial organization of cytosolic Ca 2ϩ signals is of considerable importance. Polarized cells have advantages for Ca 2ϩ studies since localized signals can be related to particular organelles. The pancreatic acinar cell is well-characterized with a clearly polarized structure and function. Since the discovery of the intracellular Ca 2ϩ -releasing function of inositol 1,4,5-trisphosphate (IP 3 ) in the pancreas in the early 1980s, this cell has become a popular study object and is now one of the best-characterized with regard to Ca 2ϩ signaling properties. Stimulation of pancreatic acinar cells with the neurotransmitter acetylcholine or the hormone cholecystokinin evokes Ca 2ϩ signals that are either local or global, depending on the agonist concentration and the length of the stimulation period. The nature of the Ca 2ϩ transport events across the basal and apical plasma membranes as well as the involvement of the endoplasmic reticulum (ER), the nucleus, the mitochondria, and the secretory granules in Ca 2ϩ signal generation and termination have become much clearer in recent years.