Structural highlights
Function
[CALM1_MOUSE] Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis. Is a regulator of voltage-dependent L-type calcium channels. Mediates calcium-dependent inactivation of CACNA1C. Positively regulates calcium-activated potassium channel activity of KCNN2. Forms a potassium channel complex with KCNQ1 and regulates electrophysiological activity of the channel via calcium-binding. Acts as a sensor to modulate the endoplasmic reticulum contacts with other organelles mediated by VMP1:ATP2A2 (By similarity).[UniProtKB:P0DP23][NEUG_MOUSE] Regulates the affinity of calmodulin for calcium. Involved in synaptic plasticity and spatial learning.[1]
Publication Abstract from PubMed
Neuromodulin (Nm) and neurogranin (Ng) are neuron-specific substrates of protein kinase C (PKC). Their interactions with Calmodulin (CaM) are crucial for learning and memory formation in neurons. Here, we report the structure of IQ peptides (24aa) of Nm/Ng complexed with CaM and their functional studies with full-length proteins. Nm/Ng and their respective IQ peptides are intrinsically unstructured; however, upon binding with CaM, IQ motifs adopt a helical conformation. Ser41 (Ser36) of Nm (Ng) is located in a negatively charged pocket in the apo CaM and, when phosphorylated, it will repel Nm/Ng from CaM. These observations explain the mechanism by which PKC-induced Ser phosphorylation blocks the association of Nm/Ng with CaM and interrupts several learning- and memory-associated functions. Moreover, the present study identified Arg as a key CaM interacting residue from Nm/Ng. This residue is crucial for CaM-mediated function, as evidenced by the inability of the Ng mutant (Arg-to-Ala) to potentiate synaptic transmission in CA1 hippocampal neurons.
Structural basis for the interaction of unstructured neuron specific substrates neuromodulin and neurogranin with calmodulin.,Kumar V, Chichili VP, Zhong L, Tang X, Velazquez-Campoy A, Sheu FS, Seetharaman J, Gerges NZ, Sivaraman J Sci Rep. 2013 Mar 6;3:1392. doi: 10.1038/srep01392. PMID:23462742[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Pak JH, Huang FL, Li J, Balschun D, Reymann KG, Chiang C, Westphal H, Huang KP. Involvement of neurogranin in the modulation of calcium/calmodulin-dependent protein kinase II, synaptic plasticity, and spatial learning: a study with knockout mice. Proc Natl Acad Sci U S A. 2000 Oct 10;97(21):11232-7. PMID:11016969 doi:http://dx.doi.org/10.1073/pnas.210184697
- ↑ Kumar V, Chichili VP, Zhong L, Tang X, Velazquez-Campoy A, Sheu FS, Seetharaman J, Gerges NZ, Sivaraman J. Structural basis for the interaction of unstructured neuron specific substrates neuromodulin and neurogranin with calmodulin. Sci Rep. 2013 Mar 6;3:1392. doi: 10.1038/srep01392. PMID:23462742 doi:http://dx.doi.org/10.1038/srep01392
