BIO 320 Lecture Notes - Lecture 20: Connexin, Skeletal Muscle, Unified Atomic Mass Unit
Document Summary
Many other extracellular signals (that do not work through gpcr or. Plcb) also trigger an increase in cytosolic ca2+ concentration during different cellular processes (e. g. , fertilization of egg, skeletal muscle contraction, neurotransmitter secretion at synapse). In some cases, ca2+ binds directly to certain proteins (e. g. , pkc) to affect their functions. In other cases, ca2+ acts through specific ca2+-binding proteins such as calmodulin. Various ca2+-binding proteins help to relay the cytosolic ca2+ signal. Ca2+/calmodulin-dependent kinases (cam-kinases) are important (but not only) targets of calmodulin. Cam-kinase ii (highly concentrated at post-synapses) is inactive in the absence of ca2+/calmodulin. Binding to ca2+/calmodulin leads to partial activation, which allows auto-phosphorylation and full activation of cam-kinase ii. Ca2+/calmodulin allows it serve as a memory trace of a prior. Cam-kinase ii is involved in some form of memory and learning. Protein kinase c (which binds ca2+ directly without calmodulin) and.
