Engineered Substrate‐Specific Delta PKC Antagonists to Enhance Cardiac Therapeutics

Qvit, Nir; Kornfeld, Opher S.; Mochly‐Rosen, Daria

doi:10.1002/anie.201605429

Cited by 21 publications

(24 citation statements)

References 39 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have previously shown that two proteins that interact usually share short sequences of homology that represent sites of both inter- and intra-molecular interactions 17,23,24 . More recently, we described a similar rational approach to develop PKC inhibitors that selectively block interaction and phosphorylation of only one protein substrate of these multi-substrate kinases 6,7,25 . Using the same approach, we rationally designed SAMβA.…”

Section: Resultsmentioning

confidence: 99%

A selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in rats

et al. 2019

Self Cite

View full text Add to dashboard Cite

We previously demonstrated that beta II protein kinase C (βIIPKC) activity is elevated in failing hearts and contributes to this pathology. Here we report that βIIPKC accumulates on the mitochondrial outer membrane and phosphorylates mitofusin 1 (Mfn1) at serine 86. Mfn1 phosphorylation results in partial loss of its GTPase activity and in a buildup of fragmented and dysfunctional mitochondria in heart failure. βIIPKC siRNA or a βIIPKC inhibitor mitigates mitochondrial fragmentation and cell death. We confirm that Mfn1-βIIPKC interaction alone is critical in inhibiting mitochondrial function and cardiac myocyte viability using SAMβA, a rationally-designed peptide that selectively antagonizes Mfn1-βIIPKC association. SAMβA treatment protects cultured neonatal and adult cardiac myocytes, but not Mfn1 knockout cells, from stress-induced death. Importantly, SAMβA treatment re-establishes mitochondrial morphology and function and improves cardiac contractility in rats with heart failure, suggesting that SAMβA may be a potential treatment for patients with heart failure.

show abstract

Section: Resultsmentioning

confidence: 99%

A selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in rats

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…We previously found that δPKC is a key mediator of IR injury, and the inhibition of δPKC activity, with the pan-inhibitor peptide δV1-1, at the time of reperfusion attenuates injury in animal models of IR, and in patients with acute myocardial infarction [ 8 , 9 ]. δPKC has multiple substrates with various, and often opposing, downstream effects [ 10 , 32 ]. cTnI is known to be phosphorylated by δPKC in IR [ 10 , 11 , 12 ].…”

Section: Discussionmentioning

confidence: 99%

“…Activation of δPKC during reperfusion induces cell death through the dysregulation of mitochondrial function, apoptosis, and oncosis; a δPKC pan-inhibitor designed in our lab (δV1-1) mitigated myocardial injury by more than 60% in preclinical models of IR injury, and in patients with acute myocardial infarction [ 8 , 9 ]. δPKC has multiple phosphorylation targets in IR, regulating cellular metabolism and mitochondrial function, with overlapping, and often opposing, downstream effects, as exemplified by a set of substrate-specific δPKC inhibitors developed in our lab to delineate these effects [ 10 ]. Among its targets, δPKC phosphorylates cTnI at serine 23/24, serine 43/45, and threonine 144, and we have previously shown that phosphorylation of cTnI by δPKC increases with IR, and cTnI phosphorylation by δPKC is thought to cause a reduction in maximal myofilament force in cardiomyocytes [ 11 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

A Selective Inhibitor of Cardiac Troponin I Phosphorylation by Delta Protein Kinase C (δPKC) as a Treatment for Ischemia-Reperfusion Injury

et al. 2022

Self Cite

View full text Add to dashboard Cite

Myocardial infarction is the leading cause of cardiovascular mortality, with myocardial injury occurring during ischemia and subsequent reperfusion (IR). We previously showed that the inhibition of protein kinase C delta (δPKC) with a pan-inhibitor (δV1-1) mitigates myocardial injury and improves mitochondrial function in animal models of IR, and in humans with acute myocardial infarction, when treated at the time of opening of the occluded blood vessel, at reperfusion. Cardiac troponin I (cTnI), a key sarcomeric protein in cardiomyocyte contraction, is phosphorylated by δPKC during reperfusion. Here, we describe a rationally-designed, selective, high-affinity, eight amino acid peptide that inhibits cTnI’s interaction with, and phosphorylation by, δPKC (ψTnI), and prevents tissue injury in a Langendorff model of myocardial infarction, ex vivo. Unexpectedly, we also found that this treatment attenuates IR-induced mitochondrial dysfunction. These data suggest that δPKC phosphorylation of cTnI is critical in IR injury, and that a cTnI/δPKC interaction inhibitor should be considered as a therapeutic target to reduce cardiac injury after myocardial infarction.

show abstract

“…Peptide inhibitors derived from docking sites and docking motifs have also been developed for the MAPK family of kinases [ 6 ]. Recently, Qvit et al demonstrated the substrate-specific phosphorylation inhibition by PKCδ using peptides of predicted docking motifs of MARCKS, Drp1, and IRS1 [ 26 ]. We anticipated that DM peptides of MYPT1 act as MYPT1-specific inhibitors against Rho-kinase.…”

Section: Discussionmentioning

confidence: 99%

Identification of the Kinase-Substrate Recognition Interface between MYPT1 and Rho-Kinase

et al. 2022

View full text Add to dashboard Cite

Protein kinases exert physiological functions through phosphorylating their specific substrates; however, the mode of kinase–substrate recognition is not fully understood. Rho-kinase is a Ser/Thr protein kinase that regulates cytoskeletal reorganization through phosphorylating myosin light chain (MLC) and the myosin phosphatase targeting subunit 1 (MYPT1) of MLC phosphatase (MLCP) and is involved in various diseases, due to its aberrant cellular contraction, morphology, and movement. Despite the importance of the prediction and identification of substrates and phosphorylation sites, understanding of the precise regularity in phosphorylation preference of Rho-kinase remains far from satisfactory. Here we analyzed the Rho-kinase–MYPT1 interaction, to understand the mode of Rho-kinase substrate recognition and found that the three short regions of MYPT1 close to phosphorylation sites (referred to as docking motifs (DMs); DM1 (DLQEAEKTIGRS), DM2 (KSQPKSIRERRRPR), and DM3 (RKARSRQAR)) are important for interactions with Rho-kinase. The phosphorylation levels of MYPT1 without DMs were reduced, and the effects were limited to the neighboring phosphorylation sites. We further demonstrated that the combination of pseudosubstrate (PS) and DM of MYPT1 (PS1 + DM3 and PS2 + DM2) serves as a potent inhibitor of Rho-kinase. The present information will be useful in identifying new substrates and developing selective Rho-kinase inhibitors.

show abstract

Engineered Substrate‐Specific Delta PKC Antagonists to Enhance Cardiac Therapeutics

Cited by 21 publications

References 39 publications

A selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in rats

A selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in rats

A Selective Inhibitor of Cardiac Troponin I Phosphorylation by Delta Protein Kinase C (δPKC) as a Treatment for Ischemia-Reperfusion Injury

Identification of the Kinase-Substrate Recognition Interface between MYPT1 and Rho-Kinase

Contact Info

Product

Resources

About