Igor Filippov

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p27 controls cell proliferation by binding and regulating nuclear cyclin-dependent kinases (CDKs). In addition, p27 interacts with other nuclear and cytoplasmic targets and has diverse biological functions. We seek to understand how the structural and dynamic properties of p27 mediate its several functions. We show that, despite showing disorder before(More)
In experiments on isolated segments or strips obtained from the guinea-pig ureter, we showed, using a sucrose-gap technique, that application of an activator of ATP-dependent potassium channels (KATP), (flocalin (PF-5), suppresses generation of action potentials (APs) by ureter smooth muscle cells (SMCs). Pre-incubation of the ureter preparations under(More)
The G-protein-dependent intracellular signal cascades of excitation in longitudinal and circular intestinal smooth muscles (SM) are compared and summarized in the present review. The key mechanism of excitation in longitudinal SM is an activation of electro-mechanical coupling, in that G-proteins, phospholipase A2, arachidonic acid, membrane-bound cyclic(More)
This paper describes an efficient NMR strategy for assigning the backbone resonances of an intrinsically unstructured protein (IUP), p21-KID, bound to its biological target, Cdk2/cyclin A. In order to overcome the challenges associated with the high molecular weight (75 kDa) and low solubility of the ternary complex (0.2 mM), we used perdeuteration, TROSY,(More)
Arf is a tumor suppressor that regulates p53 function and is a frequent target for loss in human cancers. Through two novel mechanisms, Arf inhibits the oncoprotein Hdm2, a negative regulator of p53. (1) Arf inhibits the E3 ubiquitin ligase activity of Hdm2 that leads to p53 degradation, and (2) Arf sequesters Hdm2 within nucleoli. These activities of Arf(More)
The D1A mutant of recombinant NP2 has been prepared and shown to have the expression-initiation methionine-0 cleaved during expression in E. coli, as is the case for recombinant NP4, where Ala is the first amino acid for the recombinant protein as well as for the mature native protein. The heme substituent 1H NMR chemical shifts of NP2-D1A and those of its(More)
In this work, we present a study of the influence of the protein matrix on its ability to tune the binding of small ligands such as NO, cyanide (CN(-)), and histamine to the ferric heme iron center in the NO-storage and -transport protein Nitrophorin 2 (NP2) from the salivary glands of the blood-sucking insect Rhodnius prolixus. Conventional Mössbauer(More)
TRPM8 cold receptor/channel is considered amongst the variety of receptors that support and modulate sensory function of urothelium, although the information regarding this is still quite contradictory. Here we have studied the effects of nonspecific TRPM8 activator menthol on the contractions of the smooth muscle strips of the rat bladder with intact and(More)
TRPM8 is nonselective, Ca2- permeable cationic channel, which is activated by innocuous cold and by chemical drugs imitators of cooling, menthol, icilin and cucalyptol. TRPM8 expression was detected in the smooth muscle cells of the rat vas deference with preferential localization of the TRPM8 protein to the membrane of sarcoplasmic reticulum (SR). In the(More)
We found that nonadrenergic inhibitory synaptic potentials (ISP) induced by intramural stimulation in atropine-treated smooth muscles of the guinea-pig large intestine demonstrated no changes upon the influence of an activator of adenylate cyclase, forskolin. This indicates that cAMP-dependent pathways are not involved in the generation of ISP. However, in(More)