Sorcin is an early marker of neurodegeneration, Ca dysregulation and endoplasmic reticulum stress associated to neurodegenerative diseases.

Dysregulation of calcium signaling is emerging as a key feature in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), and targeting this process may be therapeutically beneficial. Under this perspective, it is important to study proteins that regulate calcium homeostasis in the cell. Sorcin is one of the most expressed calcium-binding proteins in the human brain; its overexpression increases endoplasmic reticulum (ER) calcium concentration and decreases ER stress in the heart and in other cellular types.

Aurora A promotes chromosome congression by activating the condensin-dependent pool of KIF4A.

Aurora kinases create phosphorylation gradients within the spindle during prometaphase and anaphase, thereby locally regulating factors that promote spindle organization, chromosome condensation and movement, and cytokinesis. We show that one such factor is the kinesin KIF4A, which is present along the chromosome axes throughout mitosis and the central spindle in anaphase. These two pools of KIF4A depend on condensin I and PRC1, respectively.

Getting out of mitosis: spatial and temporal control of mitotic exit and cytokinesis by PP1 and PP2A.

Here, we will review the evidence showing that mitotic exit is initiated by regulated proteolysis and then driven by the PPP family of phosphoserine/threonine phosphatases. Rapid APC/C and ubiquitin-dependent proteolysis of cyclin B and securin initiates sister chromatid separation, the first step of mitotic exit. Because proteolysis of Aurora and Polo family kinases dependent on APC/C is relatively slow, this creates a new regulatory state, anaphase, different to G2 and M-phase.

Surface Plasmon Resonance: A Useful Strategy for the Identification of Small Molecule Argonaute 2 Protein Binders.

Surface plasmon resonance (SPR) is one of the most important techniques for the detection and the characterization of molecular interactions. SPR technology is a label-free approach for monitoring biomolecular interactions in real time. The binding of analytes to molecules immobilized on a thin metal film (ligand) determines a change in the refractive index and, therefore in the angle of extinction of light, is reflected when polarized light hits the film, monitored in real time as a change in the position of the dip in reflected intensity.

Small Molecules Targeting the miRNA-Binding Domain of Argonaute 2: From Computer-Aided Molecular Design to RNA Immunoprecipitation.

The development of small-molecule-based target therapy design for human disease and cancer is object of growing attention. Recently, specific microRNA (miRNA) mimicking compounds able to bind the miRNA-binding domain of Argonaute 2 protein (AGO2) to inhibit miRNA loading and its functional activity were described. Computer-aided molecular design techniques and RNA immunoprecipitation represent suitable approaches to identify and experimentally determine if a compound is able to impair the loading of miRNAs on AGO2 protein.

A PP2A-B55 recognition signal controls substrate dephosphorylation kinetics during mitotic exit.

PP2A-B55 is one of the major phosphatases regulating cell division. Despite its importance for temporal control during mitotic exit, how B55 substrates are recognized and differentially dephosphorylated is unclear. Using phosphoproteomics combined with kinetic modeling to extract B55-dependent rate constants, we have systematically identified B55 substrates and assigned their temporal order in mitotic exit.

Short peptides from leucyl-tRNA synthetase rescue disease-causing mitochondrial tRNA point mutations.

Mutations in mitochondrial (mt) genes coding for mt-tRNAs are responsible for a range of syndromes, for which no effective treatment is available. We recently showed that the carboxy-terminal domain (Cterm) of human mt-leucyl tRNA synthetase rescues the pathologic phenotype associated either with the m.3243A>G mutation in mt-tRNA(Leu(UUR)) or with mutations in the mt-tRNA(Ile), both of which are aminoacylated by Class I mt-aminoacyl-tRNA synthetases (mt-aaRSs).

Structural basis of Sorcin-mediated calcium-dependent signal transduction.

Sorcin is an essential penta-EF hand calcium binding protein, able to confer the multi-drug resistance phenotype to drug-sensitive cancer cells and to reduce Endoplasmic Reticulum stress and cell death. Sorcin silencing blocks cell cycle progression in mitosis and induces cell death by triggering apoptosis. Sorcin participates in the modulation of calcium homeostasis and in calcium-dependent cell signalling in normal and cancer cells.

Targeting polyamine metabolism for finding new drugs against leishmaniasis: a review.

Leishmaniasis is a neglected disease affecting more than 12 million people worldwide. The most used drugs are pentavalent antimonials that are very toxic and display the problem of drug resistance, especially in endemic regions such as Bihar in India. For this reason, it is urgent to find new and less toxic drugs against leishmaniasis.

Sorcin, a calcium binding protein involved in the multidrug resistance mechanisms in cancer cells.

Sorcin is a penta-EF hand calcium binding protein, which participates in the regulation of calcium homeostasis in cells. Sorcin regulates calcium channels and exchangers located at the plasma membrane and at the endo/sarcoplasmic reticulum (ER/SR), and allows high levels of calcium in the ER to be maintained, preventing ER stress and possibly, the unfolded protein response. Sorcin is highly expressed in the heart and in the brain, and overexpressed in many cancer cells.

Sorcin links calcium signaling to vesicle trafficking, regulates Polo-like kinase 1 and is necessary for mitosis.

Sorcin, a protein overexpressed in many multi-drug resistant cancers, dynamically localizes to distinct subcellular sites in 3T3-L1 fibroblasts during cell-cycle progression. During interphase sorcin is in the nucleus, in the plasma membrane, in endoplasmic reticulum (ER) cisternae, and in ER-derived vesicles localized along the microtubules. These vesicles are positive to RyR, SERCA, calreticulin and Rab10.

The isolated carboxy-terminal domain of human mitochondrial leucyl-tRNA synthetase rescues the pathological phenotype of mitochondrial tRNA mutations in human cells.

Mitochondrial (mt) diseases are multisystem disorders due to mutations in nuclear or mtDNA genes. Among the latter, more than 50% are located in transfer RNA (tRNA) genes and are responsible for a wide range of syndromes, for which no effective treatment is available at present. We show that three human mt aminoacyl-tRNA syntethases, namely leucyl-, valyl-, and isoleucyl-tRNA synthetase are able to improve both viability and bioenergetic proficiency of human transmitochondrial cybrid cells carrying pathogenic mutations in the mt-tRNA(Ile) gene.

Structural insights into the enzymes of the trypanothione pathway: targets for antileishmaniasis drugs.

Leishmaniasis is a neglected disease that kills 60,000 people worldwide, and which is caused by the protozoa Leishmania. The enzymes of the trypanothione pathway: trypanothione synthetase-amidase, trypanothione reductase (TR) and tryparedoxin-dependent peroxidase are absent in human hosts, and are essential for parasite survival and druggable. The most promising target is trypanothione synthetase-amidase, which has been also chemically validated.