Calmodulin-binding proteins as calpain substrates

Wang, Kevin; Villalobo, Antonio; Roufogalis, Basil D.

doi:10.1042/bj2620693

Cited by 265 publications

(172 citation statements)

References 153 publications

Supporting

Mentioning

156

Contrasting

Unclassified

Order By: Relevance

“…These 'PEST' regions are considered to be recognized by a specific protease( Particularly, calpain is a candidate for the degradation of PEST-containing proteins [14,31]. By computer analysis of the amino acid sequences using PC Gene software (Intelligenetics, Mountain View, CA), three PEST regions were predicted in the p65 subunit of NF-KB but no typical PEST region was found in the p50 subunit of NF-KB.…”

Section: Discussionmentioning

confidence: 99%

Proteolytic processing of nuclear factor κB by calpain in vitro

et al. 1996

View full text Add to dashboard Cite

Nuclear factor KB (NF-KB) is a transcription factor that is critical for the inducible expression of multiple cellular and viral genes. Using the electrophoretic mobility shift assay, we demonstrated that DNA binding activity of NF-KB was abolished by proteolysis with p-and m-calpains in vitro. The proteolysis of NF-KB by calpains and hence the abolition of its DNA binding was prevented by calpastatin, calpain inhibitor I and proteasome inhibitor. We also provided evidence that calpains degrade the Cterminal domain of NF-KB by Western blot using anti-NF-KB (~65) C-terminal antibody. These observations indicate that calpains regulate gene expression through processing of NF-KB.

show abstract

Section: Discussionmentioning

confidence: 99%

Proteolytic processing of nuclear factor κB by calpain in vitro

et al. 1996

View full text Add to dashboard Cite

show abstract

“…Calpastatin binds to these CaM homology domains and inactivates calpain (37). Interestingly, virtually all proteins that bind to CaM are also substrates for calpain (38). Calpain, calpastatin, and CaM exist in a complex with AR (Fig.…”

Section: Discussionmentioning

confidence: 99%

Calmodulin-Androgen Receptor (AR) Interaction: Calcium-Dependent, Calpain-Mediated Breakdown of AR in LNCaP Prostate Cancer Cells

Pelley¹,

Chinnakannu²,

Murthy³

et al. 2006

Cancer Research

View full text Add to dashboard Cite

Chemotherapy of prostate cancer targets androgen receptor (AR) by androgen ablation or antiandrogens, but unfortunately, it is not curative. Our attack on prostate cancer envisions the proteolytic elimination of AR, which requires a fuller understanding of AR turnover. We showed previously that calmodulin (CaM) binds to AR with important consequences for AR stability and function. To examine the involvement of Ca 2+ /CaM in the proteolytic breakdown of AR, we analyzed LNCaP cell extracts that bind to a CaM affinity column for the presence of low molecular weight forms of AR (intact AR size, f114 kDa). Using an antibody directed against the NH 2 -terminal domain (ATD) of AR on Western blots, we identified f76-kDa, f50-kDa, and 34/31-kDa polypeptides in eluates of CaM affinity columns, suggesting the presence of CaM-binding sites within the 31/34-kDa ATD of AR. Under cell-free conditions in the presence of phenylmethylsulfonyl fluoride, AR underwent Ca 2+ -dependent degradation. AR degradation was inhibited by N-acetyl-leu-leu-norleu, an inhibitor of thiol proteases, suggesting the involvement of calpain. In intact cells, AR breakdown was accelerated by raising intracellular Ca 2+ using calcimycin, and increased AR breakdown was reversed with the cell-permeable Ca 2+ chelator bis-(O-aminophenoxy)-ethane-N,N,N ¶,N ¶-tetraacetic acid tetra-(acetoxymethyl)-ester. In CaM affinity chromatography studies, the Ca 2+ -dependent protease calpain was bound to and eluted from the CaM-agarose column along with AR. Caspase-3, which plays a role in AR turnover under stress conditions, did not bind to the CaM column and was present in the proenzyme form. Similarly, AR immunoprecipitates prepared from wholecell extracts of exponentially growing LNCaP cells contained both calpain and calpastatin. Nuclear levels of calpain and calpastatin (its endogenous inhibitor) changed in a reciprocal fashion as synchronized LNCaP cells progressed from G 1 to S phase. These reciprocal changes correlated with changes in AR level, which increased in late G 1 phase and decreased as S phase progressed. Taken together, these observations suggest potential involvement of AR-bound CaM in calciumcontrolled, calpain-mediated breakdown of AR in prostate cancer cells. (Cancer Res 2006; 66(24): 11754-62)

show abstract

“…Calmodulin-binding proteins are especially vulnerable to calpain cleavage (Wang et al, 1989). Calpain is activated during necrosis (Wang et al, 199627) and in many cell types undergoing apoptosis (Sarin et al, 1993;Squier et al, 1994) including SH-SY5Y cells .…”

Section: K M Mcginnis Et Almentioning

confidence: 99%

Alterations of Extracellular Calcium Elicit Selective Modes of Cell Death and Protease Activation in SH‐SY5Y Human Neuroblastoma Cells

McGinnis¹,

Wang²,

Gnegy³

1999

Journal of Neurochemistry

View full text Add to dashboard Cite

Abstract:The role of intracellular Ca2+ homeostasis in mechanisms of neuronal cell death and cysteine protease activation was investigated in SH-SY5Y human neuroblastoma cells. Cells were incubated in 2 mM EGTA to lower intracellular Ca2+ or 5 mM CaCI, to raise it. Cell death and activation of calpain and caspase-3 were measured. Both EGTA and excess CaCI, elicited cell death. EGTA induced DNA laddering and an increase in caspase-3-like, but not calpain, activity. Pan-caspase inhibitors protected against EGTA-, but not CaCI,-, induced cell death. Conversely, excess Ca2+ elicited necrosis and activated calpain but not caspase-3. Calpain inhibitors did not preserve cell viability. Ca2+ was the death-mediating factor, because restoration of extracelMar Ca2+ protected against cell death induced by EGTA and blockade of Ca2+ channels by Ni'+ protected against that induced by high Ca2+. We conclude that the EGTA treatment lowered intracellular Ca2+ and elicited caspase-3-like protease activity, which led to apoptosis. Conversely, excess extracellular Ca2+ entered Ca2+ channels and increased intracellular Ca2+ leading to calpain activation and necrosis. The mode of cell death and protease activation in response to changing Ca2+ were selective and mutually exclusive, demonstrating that these are useful models to individually investigate apoptosis and necrosis. Key Words: Apoptosis-Necrosis-Calpain-Caspase-3-Ca2+ homeostasis-Neuronal death.

show abstract

Calmodulin-binding proteins as calpain substrates

Abstract: (ii) proteolysis of four out of the five enzymes in the absence of calmodulin activates their respective enzymic activities (Table 2). In fact, earlier studies revealed that Vol.

Cited by 265 publications

References 153 publications

Proteolytic processing of nuclear factor κB by calpain in vitro

Proteolytic processing of nuclear factor κB by calpain in vitro

Calmodulin-Androgen Receptor (AR) Interaction: Calcium-Dependent, Calpain-Mediated Breakdown of AR in LNCaP Prostate Cancer Cells

Alterations of Extracellular Calcium Elicit Selective Modes of Cell Death and Protease Activation in SH‐SY5Y Human Neuroblastoma Cells

Contact Info

Product

Resources

About