Calmodulin bound to stress fibers but not microtubules involves regulation of cell morphology and motility

Yuan, Jun; Shi, Guoxin; Shao, Yue; Dai, Gaole; Wei, Jun-Ning; Chang, Donald C.; Li, Chao Jun

doi:10.1016/j.biocel.2007.08.004

Cited by 9 publications

(7 citation statements)

References 18 publications

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“…It is important to note that, despite the common referral of KN-62 in the literature as a CaMKII inhibitor (19), the blocker appears to target a number of calmodulin-dependent and calmodulin-independent proteins such as CaMKIV and -V (19), glycogen synthase kinase 3b, p38-regulated/activated kinase, and mitogen-activated protein kinase-activated protein kinase 2 (7). We also cannot rule out the possibility that the actions of KN-62 are being mediated by other calmodulin-binding proteins such as adenylyl cyclases (16) or actin polymerization (49), whose sensitivity to KN-62 is not known, or an effect unrelated to calmodulin binding. A known calmodulin-independent effect of KN-62 is inhibition of P2 purinergic receptors (40), an effect that has been shown to decrease cytosolic Ca 2ϩ (34).…”

Section: Kn-62 Inhibited An Energy-requiring Step Downstream Of L-typmentioning

confidence: 98%

A highly energetic process couples calcium influx through L-type calcium channels to insulin secretion in pancreatic β-cells

Jung¹,

Reed²,

Sweet³

2009

American Journal of Physiology-Endocrinology and Metabolism

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Jung SR, Reed BJ, Sweet IR. A highly energetic process couples calcium influx through L-type calcium channels to insulin secretion in pancreatic ␤-cells. Am J Physiol Endocrinol Metab 297: E717-E727, 2009. First published July 7, 2009 doi:10.1152/ajpendo.00282.2009 ) influx is required for the sustained secretion of insulin and is accompanied by a large rate of energy usage. We hypothesize that the energy usage reflects a process [Ca 2ϩ /metabolic coupling process (CMCP)] that couples Ca 2ϩ to insulin secretion by pancreatic islets. The aim of the study was to test this hypothesis by testing the effect of inhibiting candidate Ca 2ϩ -sensitive proteins proposed to play a critical role in the CMCP. The effects of the inhibitors on oxygen consumption rate (OCR), a reflection of ATP usage, and insulin secretion rate (ISR) were compared with those seen when L-type Ca 2ϩ channels were blocked with nimodipine. We reasoned that if a downstream Ca 2ϩ -regulated site was responsible for the OCR associated with the CMCP, then its inhibition should mimic the effect of nimodipine. Consistent with previous findings, nimodipine decreased glucose-stimulated OCR by 36% and cytosolic Ca 2ϩ by 46% and completely suppressed ISR in rat pancreatic islets. Inhibitors of three calmodulin-sensitive proteins (myosin light-chain kinase, calcineurin, and Ca 2ϩ /calmodulin-dependent protein kinase II) did not meet the criteria. In contrast, KN-62 severed the connection between Ca 2ϩ influx, OCR, and ISR without interfering with Ca 2ϩ influx. In the presence of nimodipine or KN-62, potentiators of ISR, acetylcholine, GLP-1, and arginine had little effect on insulin secretion, suggesting that the CMCP is also essential for the amplification of ISR. In conclusion, a KN-62-sensitive process directly mediates the effects of Ca 2ϩ influx via L-type Ca 2ϩ

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Section: Kn-62 Inhibited An Energy-requiring Step Downstream Of L-typmentioning

confidence: 98%

A highly energetic process couples calcium influx through L-type calcium channels to insulin secretion in pancreatic β-cells

Jung¹,

Reed²,

Sweet³

2009

American Journal of Physiology-Endocrinology and Metabolism

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“…These responses play a critical role in transducing mechanical signals applied at the cell surface into intracellular signals that are necessary for increased gene expression and new bone formation (Pavalko et al 1998). Polymerization of actin is regulated by actinassociated proteins, such as non-phosphorylated calponin h1 (CNh1) (Kaneko et al 2000), calmodulin (Yuan et al 2008), and Rho family proteins (Burridge and Wennerberg 2004).…”

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confidence: 99%

Tail-Suspended Mice Lacking Calponin H1 Experience Decreased Bone Loss

Yotsumoto¹,

Takeoka

Yokoyama

2010

Tohoku J. Exp. Med.

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“…Our previous results show that the localization of CaM is controlled in a spatio-temporally specific manner (Li et al 1999;Yu et al 2004;Shen et al 2007;Yuan et al 2008), indicating that specific CaM-binding proteins may also function the same way. Through the IP-MALDI-TOF-MS strategy, we identified 41 CaMBPs and further confirmed some of them with immunoprecipitation, western blot and FRET analysis to exclude non-specifically binding proteins, among which fifteen are cell-cycle-specific in a calciumdependent or -independent manner.…”

Section: Discussionmentioning

confidence: 86%

“…For example, CaM can bind with beta-actin in a Ca 2+ independent manner. Our previous study has implied that actin interaction with CaM is essential for cell adhesion and migration (Yuan et al 2008). Some CaMBPs that have IQ or IQ-like motifs may be required for scission of the residual cytoplasmic bridge to complete cytokinesis (Nagasaki and Uyeda 2004).…”

Section: Discussionmentioning

confidence: 99%

“…CaM regulates the G2/M transition, spindle structure maintenance, furrow formation, cytokinesis completion, cell morphology and migration, etc, which are dependent upon the distribution of CaM in the nucleus, furrow and central, intracellular bridge and stress fibers (Li et al 1999;Yu et al 2004;Shen et al 2007;Yuan et al 2008).CaM itself has no enzymatic activity and it is believed that the spatiotemporal interaction of CaM and its targets is essential for CaM's regulatory function (Török et al 1998). CaM can alter the conformation of its partner when it binds to a relatively small region of the target protein with high affinity.…”

Section: Introductionmentioning

confidence: 99%

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The association of CaM and Hsp70 regulates S-phase arrest and apoptosis in a spatially and temporally dependent manner in human cells

Huang

Wei

Peng

et al. 2009

Cell Stress and Chaperones

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The cell cycle is controlled by regulators functioning at the right time and at the right place. We have found that calmodulin (CaM) has specific distribution patterns during different cell-cycle stages. Here, we identify cell-cycle-specific binding proteins of CaM and examine their function during cell-cycle progression. We first applied immunoprecipitation methods to isolate CaMbinding proteins from cell lysates obtained at different cell-cycle phases and then identified these proteins using mass spectrometry methods. A total of 41 proteins were identified including zinc finger proteins, ribosomal proteins, and heat shock proteins operating in a Ca 2+ -dependent or independent manner. Fifteen proteins were shown to interact with CaM in a cell-phase-specific manner. The association of the selected proteins and CaM were confirmed with in vitro immunoprecipitation and immunostaining methods. One of the identified proteins, heat shock protein 70 (Hsp70), was further studied with respect to its cell-cycle-related function. In vivo fluorescence resonance energy transfer (FRET) analysis showed that the interaction of CaM and Hsp70 was found in the nucleus during the S phase. Overexpression of Hsp70 is shown to arrest cells at S phase and, thus, induce cell apoptosis. When we disrupted the CaM-Hsp70 association with HSP70 truncation without the CaM-binding domain, we found that S-phase arrest and apoptosis could be rescued. The results suggest that the spatial and temporal association of CaM and Hsp70 can regulate cell-cycle progression and cell apoptosis.

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Calmodulin bound to stress fibers but not microtubules involves regulation of cell morphology and motility

Cited by 9 publications

References 18 publications

A highly energetic process couples calcium influx through L-type calcium channels to insulin secretion in pancreatic β-cells

A highly energetic process couples calcium influx through L-type calcium channels to insulin secretion in pancreatic β-cells

Tail-Suspended Mice Lacking Calponin H1 Experience Decreased Bone Loss

The association of CaM and Hsp70 regulates S-phase arrest and apoptosis in a spatially and temporally dependent manner in human cells

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