Exploring the Role of CaMKIV in Homeostatic Plasticity

Calcium Signalling in Heart and Vessels: Role of Calmodulin and Downstream Calmodulin-Dependent Protein Kinases

Cardiovascular disease is the major cause of death worldwide. The success of medication and other preventive measures introduced in the last century have not yet halted the epidemic of cardiovascular disease. Although the molecular mechanisms of the pathophysiology of the heart and vessels have been extensively studied, the burden of ischemic cardiovascular conditions has risen to become a top cause of morbidity and mortality. Calcium has important functions in the cardiovascular system. Calcium is involved in the mechanism of excitation-contraction coupling that regulates numerous events, ranging from the production of action potentials to the contraction of cardiomyocytes and vascular smooth muscle cells. Both in the heart and vessels, the rise of intracellular calcium is sensed by calmodulin, a protein that regulates and activates downstream kinases involved in regulating calcium signalling. Among them is the calcium calmodulin kinase family, which is involved in the regulation of cardiac functions. In this review, we present the current literature regarding the role of calcium/calmodulin pathways in the heart and vessels with the aim to summarize our mechanistic understanding of this process and to open novel avenues for research.

Electrophysiological study of the interactive role of the cannabinoid breakdown inhibitors and L-type calcium channels on granular neurons in the hippocampal dentate gyrus in rats

The interaction between L-type voltage-dependent Ca²⁺ channels and the endocannabinoid system (eCs) in synaptic plasticity is controversial. In the present research, the impact of acute administration of URB597, as an endocannabinoid breakdown inhibitor, was evaluated after chronic injection of verapamil, as a Ca²⁺ channels blocker, on inducing long-term potentiation (LTP) in the rat's hippocampal dentate gyrus (DG). Treatment of male Wistar rats was done using intraperitoneal(i.p) injection of verapamil hydrochloride (n = 8) and saline (n = 10), as the solvent of verapamil once a day within 13 days. Anesthetization was done by i.p injection of urethane and the rats were located in the stereotaxic apparatus for surgery, electrode implantation, and field potential recording. After observing a steady-state baseline response, saline or URB597 were injected (n = 9). Measurement of the population spike (PS) amplitude and slope of field excitatory postsynaptic potentials (fEPSPs) in the DG region was performed as a result of perforant pathway (PP) stimulation. Our treatments could inhibit LTP. Our results indicated that the chronic administration of verapamil produced a significant decrease in the slope of fEPSP and PS amplitude. Also, acute URB597 administration decreased the slope of fEPSP and PS amplitude compared to the saline group. Moreover, URB597 administration in combination with chronic administration of verapamil produced a greater decrease in fEPSP slope and PS amplitude than the saline group. These findings indicated that verapamil and URB597 disrupted LTP induction in the DG. Moreover, an interaction was observed between Ca²⁺ channels and eCs. Therefore, the eCs possibly play a selective role in synaptic plasticity.

The Calcium/Calmodulin-Dependent Kinases II and IV as Therapeutic Targets in Neurodegenerative and Neuropsychiatric Disorders

CaMKII and CaMKIV are calcium/calmodulin-dependent kinases playing a rudimentary role in many regulatory processes in the organism. These kinases attract increasing interest due to their involvement primarily in memory and plasticity and various cellular functions. Although CaMKII and CaMKIV are mostly recognized as the important cogs in a memory machine, little is known about their effect on mood and role in neuropsychiatric diseases etiology. Here, we aimed to review the structure and functions of CaMKII and CaMKIV, as well as how these kinases modulate the animals’ behavior to promote antidepressant-like, anxiolytic-like, and procognitive effects. The review will help in the understanding of the roles of the above kinases in the selected neurodegenerative and neuropsychiatric disorders, and this knowledge can be used in future drug design.

Interplay Between Calcium and AMPK Signaling in Human Cytomegalovirus Infection

Calcium signaling and the AMP-activated protein kinase (AMPK) signaling networks broadly regulate numerous aspects of cell biology. Human Cytomegalovirus (HCMV) infection has been found to actively manipulate the calcium-AMPK signaling axis to support infection. Many HCMV genes have been linked to modulating calcium signaling, and HCMV infection has been found to be reliant on calcium signaling and AMPK activation. Here, we focus on the cell biology of calcium and AMPK signaling and what is currently known about how HCMV modulates these pathways to support HCMV infection and potentially contribute to oncomodulation.

In Depth Analysis of Kinase Cross Screening Data to Identify CAMKK2 Inhibitory Scaffolds

The calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) activates CAMK1, CAMK4, AMPK, and AKT, leading to numerous physiological responses. The deregulation of CAMKK2 is linked to several diseases, suggesting the utility of CAMKK2 inhibitors for oncological, metabolic and inflammatory indications. In this work, we demonstrate that STO-609, frequently described as a selective inhibitor for CAMKK2, potently inhibits a significant number of other kinases. Through an analysis of literature and public databases, we have identified other potent CAMKK2 inhibitors and verified their activities in differential scanning fluorimetry and enzyme inhibition assays. These inhibitors are potential starting points for the development of selective CAMKK2 inhibitors and will lead to tools that delineate the roles of this kinase in disease biology.

Regulation of Multifunctional Calcium/Calmodulin Stimulated Protein Kinases by Molecular Targeting

Multifunctional calcium/calmodulin-stimulated protein kinases control a broad range of cellular functions in a multitude of cell types. This family of kinases contain several structural similarities and all are regulated by phosphorylation, which either activates, inhibits or modulates their kinase activity. As these protein kinases are widely or ubiquitously expressed, and yet regulate a broad range of different cellular functions, additional levels of regulation exist that control these cell-specific functions. Of particular importance for this specificity of function for multifunctional kinases is the expression of specific binding proteins that mediate molecular targeting. These molecular targeting mechanisms allow pools of kinase in different cells, or parts of a cell, to respond differently to activation and produce different functional outcomes.

The Multi-Functional Calcium/Calmodulin Stimulated Protein Kinase (CaMK) Family: Emerging Targets for Anti-Cancer Therapeutic Intervention

The importance of Ca²⁺ signalling in key events of cancer cell function and tumour progression, such as proliferation, migration, invasion and survival, has recently begun to be appreciated. Many cellular Ca²⁺-stimulated signalling cascades utilise the intermediate, calmodulin (CaM). The Ca²⁺/CaM complex binds and activates a variety of enzymes, including members of the multifunctional Ca²⁺/calmodulin-stimulated protein kinase (CaMK) family. These enzymes control a broad range of cancer-related functions in a multitude of tumour types. Herein, we explore the cancer-related functions of these kinases and discuss their potential as targets for therapeutic intervention.