Peptide Truncation Leads to a Twist and an Unusual Increase in Affinity for Casitas B-Lineage Lymphoma Tyrosine Kinase Binding Domain

Kumar, Eric A.; Yuan, Zhengrong; Palermo, Nicholas Y.; Dong, Lin; Ahmad, Gulzar; Lokesh, G.L.; Kolar, Carol; Kizhake, Smitha; Borgstahl, Gloria E. O.; Band, Hamid; Natarajan, Amarnath

doi:10.1021/jm300078z

Cited by 13 publications

(13 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Based on this, Kumar et al . are developing strategies to identify small molecules or peptides that bind the Cbl TKB and block interaction with the RTK (53, 54). The efficacy of such an approach remains to be tested.…”

Section: Clinical-translational Advancesmentioning

confidence: 99%

Molecular Pathways: Cbl Proteins in Tumorigenesis and Antitumor Immunity—Opportunities for Cancer Treatment

Liyasova

Lipkowitz

2015

Clinical Cancer Research

View full text Add to dashboard Cite

The Cbl proteins are a family of ubiquitin ligases (E3s) that regulate signaling through many tyrosine kinase dependent pathways. A predominant function is to negatively regulate receptor tyrosine kinase (RTK) signaling by ubiquitination of active RTKs, targeting them for trafficking to the lysosome for degradation. Also, Cbl-mediated ubiquitination can regulate signaling protein function by altered cellular localization of proteins without degradation. In addition to their role as E3s, Cbl proteins play a positive role in signaling by acting as adaptor proteins which can recruit signaling molecules to the active RTKs. Cbl-b, a second family member, negatively regulates the costimulatory pathway of CD8 T-cells and also negatively regulates Natural Killer (NK) cell function. The different functions of Cbl proteins, and their roles both in the development of cancer and the regulation of immune responses provide multiple therapeutic opportunities. Mutations in Cbl which inactivate the negative E3 function while maintaining the positive adaptor function have been described in approximately 5% of myeloid neoplasms. Understanding how the signaling pathways (e.g. Fms-like tyrosine kinase 3 (Flt3), PI-3 kinase, and signal transducer and activator of transcription (Stat)) are dysregulated by these mutations in Cbl has identified potential targets for therapy of myeloid neoplasms. Conversely, the loss of Cbl-b leads to increased adaptive and innate antitumor immunity suggesting that inhibiting Cbl-b may be a means to increase antitumor immunity across a wide variety of tumors. Thus, targeting the pathways regulated by Cbl proteins may provide attractive opportunities for treating cancer.

show abstract

Section: Clinical-translational Advancesmentioning

confidence: 99%

Molecular Pathways: Cbl Proteins in Tumorigenesis and Antitumor Immunity—Opportunities for Cancer Treatment

Liyasova

Lipkowitz

2015

Clinical Cancer Research

View full text Add to dashboard Cite

show abstract

“…Since the objective of these studies is to develop a new strategy for delivering small molecules and/or peptides to the corneal epithelium, we tested the ability of these liposomes to encapsulate a 13 amino acid, fluorescently-tagged peptide (described in Material and Methods), that was originally designed to enhance growth factor receptor-mediated signalling (Kumar et al, 2012). However, the peptide’s instability in the cytosol precluded that function.…”

Section: Resultsmentioning

confidence: 99%

Preparation and optimisation of anionic liposomes for delivery of small peptides and cDNA to human corneal epithelial cells

Neves

Duan

Voelker

et al. 2016

Journal of Microencapsulation

View full text Add to dashboard Cite

Drug delivery to corneal epithelial cells is challenging due to the intrinsic mechanisms that protect the eye. Here we report a novel liposomal formulation to encapsulate and deliver a short sequence peptide into human corneal epithelial cells (hTCEpi). Using a mixture of Phosphatidylcholine/Caproylamine/Dioleoylphosphatidylethanolamine (PC/CAP/DOPE), we encapsulated a fluorescent peptide, resulting in anionic liposomes with an average size of 138.8 ± 34 nm and a charge of −18.2 ± 1.3 mV. After 2 h incubation with the peptide-encapsulated liposomes, 66% of corneal epithelial (hTCEpi) cells internalized the FITC-labelled peptide, demonstrating the ability of this formulation to effectively deliver peptide to hTCEpi cells. Additionally, lipoplexes (liposomes complexed with plasmid DNA) were also able to transfect hTCEpi cells, albeit at a modest level (8% of the cells). Here, we describe this novel anionic liposomal formulation intended to enhance the delivery of small cargo molecules in situ.

show abstract

“…Design and development of c-Cbl regulators is an active field of study because c-Cbl is associated with multiple diseases including obesity, diabetes and cancer [8], [11]–[13]. There are reports of assays being developed to screen the c-Cbl TKB domain indictors [14], [15].…”

Section: Discussionmentioning

confidence: 99%

Development of a Fluorescence Polarization Based High-Throughput Assay to Identify Casitas B-Lineage Lymphoma RING Domain Regulators

et al. 2013

View full text Add to dashboard Cite

The E3 ubiquitin protein ligase Casitas B-lineage Lymphoma (Cbl) proteins and their binding partners play an important role in regulating signal transduction pathways. It is important to utilize regulators to study the protein-protein interactions (PPIs) between these proteins. However, finding specific small-molecule regulators of PPIs remains a significant challenge due to the fact that the interfaces involved in PPIs are not well suited for effective small molecule binding. We report the development of a competitive, homogeneous, high-throughput fluorescence polarization (FP) assay to identify small molecule regulators of Cbl (RING) domain. The FP assay was used to measure binding affinities and inhibition constants of UbCH7 peptides and small molecule regulators of Cbl (RING) domains, respectively. In order to rule out promiscuous, aggregation-based inhibition, two assay conditions were developed and compared side by side. Under optimized conditions, we screened a 10,000 natural compound library in detergent-free and detergent-present (0.01% Triton X-100) systems. The results indicate that the detergent-present system is more suitable for high-throughput screens. Three potential compounds, methylprotodioscin, leonuride and catalpol, have been identified that bind to Cbl (RING) domain and interfere with the Cbl (RING)-UbCH7 protein-protein interaction.

show abstract

Peptide Truncation Leads to a Twist and an Unusual Increase in Affinity for Casitas B-Lineage Lymphoma Tyrosine Kinase Binding Domain

Cited by 13 publications

References 31 publications

Molecular Pathways: Cbl Proteins in Tumorigenesis and Antitumor Immunity—Opportunities for Cancer Treatment

Molecular Pathways: Cbl Proteins in Tumorigenesis and Antitumor Immunity—Opportunities for Cancer Treatment

Preparation and optimisation of anionic liposomes for delivery of small peptides and cDNA to human corneal epithelial cells

Development of a Fluorescence Polarization Based High-Throughput Assay to Identify Casitas B-Lineage Lymphoma RING Domain Regulators

Contact Info

Product

Resources

About