A Ca 2+ Sensor for Exocytosis

Properties of Ca(2+)-dependent exocytosis in cultured astrocytes.

Astrocytes, a subtype of glial cells, have numerous characteristics that were previously considered exclusive for neurons. One of these characteristics is a cytosolic [Ca2+] oscillation that controls the release of the chemical transmitter glutamate and atrial natriuretic peptide. These chemical messengers appear to be released from astrocytes via Ca(2+)-dependent exocytosis. In the present stu...

Ca Current versus Ca Channel Cooperativity of Exocytosis

Victor Matveev,1 Richard Bertram,2,3,4 and Arthur Sherman5 1Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, 2Department of Mathematics and Programs in 3Neuroscience and 4Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, and 5Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney...

Insulin Secretion : A High - affinity Ca 2 Sensor After All ?

Insulin is secreted from the -cells of the pancreatic islets by Ca 2 -dependent exocytosis of large dense core vesicles (LDCVs) (Ämmälä et al., 1993), a process that is triggered by glucose-induced electrical activity (Henquin and Meissner, 1984). In response to a step elevation of glucose, insulin secretion follows a characteristic biphasic time course (Curry et al., 1968): an initial transien...

Cell biology of Ca-triggered exocytosis

Ca triggers many forms of exocytosis in different types of eukaryotic cells, for example synaptic vesicle exocytosis in neurons, granule exocytosis in mast cells, and hormone exocytosis in endocrine cells. Work over the past two decades has shown that synaptotagmins function as the primary Ca-sensors for most of these forms of exocytosis, and that synaptotagmins act via Ca-dependent interaction...

v-SNARE Actions during Ca-Triggered Exocytosis