Cytohesin Inhibitor II, Cyplecksin 2

Cell permeable: yes

Primary Target
pleckstrin homology domain of the cytohesin family

Reversible: no

Toxicity: Standard Handling (A)

A cell-permeable 5-bromobarbiturate that selectively and covalently modifies the pleckstrin homology (PH) domain of the cytohesin family (K_d ~ 2 µM to cytohesin-1 labeled with Alexa647) and irreversibly inhibits its function. Prevents the interaction cytohesin-1 PH, and to cytohesins 1 and 2 lacking the short C-terminal polybasic region with PIP3 and PIP2. Blocks insulin-dependent cytohesin-2-GFP translocation to plasma membrane in HeLa cells (~50 µM). Does not recognize or show any binding to T-lymphoma invasive and metastasis inducing protein 1 (Tiam)-DH-PH and shows poor affinity towards Sec7 domain of cytohesin-2. Cytohesins Inhibitor SecinH3 is also available (>Cat. No. 565725).

Please note that the molecular weight for this compound is batch-specific due to variable water content.

A cell-permeable 5-bromobarbiturate that targets the PH domain of cytohesin family small GEFs (K_d ~2 µM in binding assay using Cyth1 PH domain aa259-381) via covalent interaction and effectively competes against both PIP₂ and PIP₃ for Cyth PH domain binding (IC₅₀ ≤10 µM against 30 nM PIP₂; [Cyth1 PH] = 250 nM), while exhibiting no affinity toward Tiam1 DH-PH domain and displaying little potency against GEP100-PH/PIP₂, DAGK- PH/PIP₂, ARHGAP25-PH/PIP₃, IRS1-PH/PIP₂, Pleckstrin-PH/PIP₃, or Akt2/PIP₃ interaction even at concentrations as high as 100 µM. Overnight pretreatment (50 µM) prior to insulin stimulation (100 nM for 10 min) is shown to greatly inhibit insulin-induced Cyth2 plasma membrane translocation by 83% in HeLa Cyth2-GFP transfectants. Greatly complements the Sec7 domain-targeting SecinH3 (Cat. No. 565725) in studying Cytohesins-mediated cellular signaling events.

Hussein, M., et al. 2013. Angew. Chem. Int. Ed.,52, 9529.

Packaged under inert gas

Following reconstitution, aliquot and freeze (-70°C). Stock solutions are stable for up to 6 months at -70°C.

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