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M Ferrone

Publications and source records attributed to M Ferrone.

16 recordsLinked to original sources
PubMed2006

Functional analyses and molecular modeling of two c-Kit mutations responsible for imatinib secondary resistance in GIST patients.

Imatinib-acquired resistance related to the presence of secondary point mutations has become a frequent event in gastrointestinal stromal tumors. Here, transient transfection experiments with plasmids carrying two different KIT-acquired point mutations were performed along with immunoprecipitation of total protein extracts, derived from imatinib-treated and untreated cells. The molecular mechanics/Poisson Boltzmann surface area computational techniques were applied to study the interactions of the wild-type and mutated receptors with imatinib at the molecular level. Biochemical analyses showed KIT phosphorylation in cells transfected with vectors carrying the specific mutant genes. Imatinib treatment demonstrated that T670I was insensitive to the drug at all the applied concentrations, whereas V654A was inhibited by 6 microM of imatinib. The modeling of the mutated receptors revealed that both substitutions affect imatinib-binding site, but to a different extent: T670I substantially modifies the binding pocket, whereas V654A induces only relatively confined structural changes. We demonstrated that T670I and V654A cause indeed imatinib-acquired resistance and that the former is more resistant to imatinib than the latter. The application of molecular simulations allowed us to quantify the interactions between the mutated receptors and imatinib, and to propose a molecular rationale for this type of drug resistance.

Antineoplastic Agents↗
PubMed2004

A polymorphism of the hypocretin receptor 2 gene is associated with cluster headache.

Several polymorphisms of the hypocretin/orexin system genes were evaluated in 109 cluster headache patients and 211 controls. The 1246 G>A polymorphism of the gene was significantly different between cases and controls. Homozygosity for the G allele was associated with an increased disease risk (OR: 6.79, 95% CI, 2.25 to 22.99). The data suggest that the HCRTR2 gene or a linked locus significantly modulates the risk for cluster headache.

Adult↗
PubMed2001

The tumor autocrine motility factor receptor, gp78, is a ubiquitin protein ligase implicated in degradation from the endoplasmic reticulum.

gp78, also known as the tumor autocrine motility factor receptor, is a transmembrane protein whose expression is correlated with tumor metastasis. We establish that gp78 is a RING finger-dependent ubiquitin protein ligase (E3) of the endoplasmic reticulum (ER). Consistent with this, gp78 specifically recruits MmUBC7, a ubiquitin-conjugating enzyme (E2) implicated in ER-associated degradation (ERAD), through a region distinct from the RING finger. gp78 can target itself for proteasomal degradation in a RING finger- and MmUBC7-dependent manner. Importantly, gp78 can also mediate degradation of CD3-delta, a well-characterized ERAD substrate. In contrast, gp78 lacking an intact RING finger or its multiple membrane-spanning domains stabilizes CD3-delta. gp78 has thus been found to be an example of a mammalian cellular E3 intrinsic to the ER, suggesting a potential link between ubiquitylation, ERAD, and metastasis.

Animals↗
PubMed1999

Polyvariant mutant CFTR genes in patients with chronic pancreatitis.

Several authors have reported an association between mutations of the cystic fibrosis transmembrane conductance regulator gene (CFTR) and chronic pancreatitis. CFTR gene transcription and protein efficiency are influenced by two polymorphic loci, (TG)m and M470V, other than the T5 allele, whose role is already well-established. The TG11/T5 haplotype is commonly found in healthy subjects, while the TG12/T5/V470 and TG13/T5/V470 haplotypes are present in congenital bilateral absence of the vas deferens (CBAVD) patients. While the T5 allele is a mutation that is over-represented in patients with chronic pancreatitis, no data are available concerning the possible allelic preference at the other two polymorphic loci, (TG)m and M470V, in these patients. For this reason, we screened 39 patients with chronic pancreatitis for the most common CFTR mutations found so far in the Italian population; in addition, we examined the length of the polypyrimidine (poly-T) tract in intron 8, the (TG)m length and the M or V codon at position 470. CFTR mutations were found in 3 patients. Poly-T variant typing identified genotype T5/T7 in 5 patients and T5/T9 in 1 patient. Direct sequencing of intron 8 in patients with the T5 variant revealed the TG12/T5/V470//TG11/T7/V470 genotype in 5 patients and TG10/T9//TG11,T5 genotype in 1 patient. In patients with chronic pancreatitis, the T5 allele is frequently associated with TG12 and V470, a haplotype already reported in CBAVD cases and quite uncommon in healthy subjects.

Adult↗
PubMed1998

Congenital bilateral absence of vas deferens with a new missense mutation (P499A) in the CFTR gene.

We describe a congenital bilateral absence of the vas deferens (CBAVD) patient with a compound heterozygosity in the cystic fibrosis transmembrane regulator (CFTR) gene for a stop mutation W1282X and a new missense mutation P499A. The P499A is interpreted as a mild mutation whose phenotypic effects, in this case limited to the development of wolffian duct derivatives, are revealed only in combination with a severe CFTR mutation.

Adult↗
PubMed1996

Prenatal diagnosis of limb-girdle muscular dystrophy type 2A.

A branch of a highly inbred family was referred for prenatal counseling with an initial misdiagnosis of Becker Muscular Dystrophy (BMD) due to the limited clinical and laboratory data obtained in pre-dystrophin era and hidden family information. In a second branch of the family with a diagnosis of limb-girdle muscular dystrophy type 2A (LGMD2A) molecular studies revealed a homozygous 550 delta A mutation in the calcium-activated neutral protease 3 (calpain 3, CANP3) gene in the affected members. Finally, in the third branch of the family, it turned out that both parents were heterozygous for the 550 delta A mutation and the 13-week-old fetus was homozygous. The same mutation subsequently also was found in the first branch of the family. The parents were informed that the risk of their child of developing the disease would be very high given that he was carrying the same homozygous mutation of the other affected members. They were informed also that in another population (in Reunion Island) the same disease does not necessarily follow such a simple pattern of inheritance. After counseling the parents decided to terminate the pregnancy.

Adult↗
PubMed1995

Intercellular adhesion molecule-1 dimerization and its consequences for adhesion mediated by lymphocyte function associated-1.

Intercellular adhesion molecule-1 (ICAM-1, CD54) is a ligand for the integrins lymphocyte function associated-1 (LFA-1, CD11a/CD18) and complement receptor-3 (Mac-1, CD11b/CD18) making it an important participant in many immune and inflammatory processes. Modified recombinant soluble ICAM-1 formed dimers. This result indicated that the ectodomain of ICAM-1 contains homophilic interaction sites. Soluble ICAM-1 dimers bind to solid-phase purified LFA-1 with high avidity (dissociation constant [Kd] = 8 nM) in contrast to soluble ICAM-1 monomers whose binding was not measurable. Cell surface ICAM-1 was found to be dimeric based on two distinct criteria. First, a monoclonal antibody specific for monomeric soluble ICAM-1, CA7, binds normal ICAM-1 poorly at the cell surface; this antibody, however, binds strongly to two mutant forms of ICAM-1 when expressed at the cell surface, thus identifying elements required for dimer formation. Second, chemical cross-linking of cell surface ICAM-1 on transfected cells and tumor necrosis factor-activated endothelial cells results in conversion of a portion of ICAM-1 to a covalent dimer. Cell surface ICAM-1 dimers are more potent ligands for LFA-1-dependent adhesion than ICAM-1 monomers. While many extracellular matrix-associated ligands of integrins are multimeric, this is the first evidence of specific, functionally important homodimerization of a cell surface integrin ligand.

Animals↗
PubMed1995

Carrier detection of Duchenne muscular dystrophy through analysis of DNA from deciduous teeth of a dead affected child.

The sister of a child affected by Duchenne muscular dystrophy (DMD) was referred for genetic counselling to assess the risk of her being a carrier. Her brother had died 15 years previously at the age of 8. There were no other affected males in the family. There were no methods for DNA investigation at the time of the child's death and the family had never been studied for linkage with polymorphic probes on the chromosomal region Xp21. The only tissue from which an assessment of the risk could be made by DNA linkage analysis was two of the child's deciduous teeth that the parents had kept. DNA was extracted using a protocol described for the recovery of ancient DNA from museum specimens and archaeological finds. Multiplex amplification did not reveal deletions in 19 exons spanning the hot-spot regions for deletions within the dystrophin gene in Xp21. Linkage analysis using three highly polymorphic microsatellites demonstrated that the sister had not received the X chromosome borne by her brother. These results show that DNA extracted from teeth is a reliable source for molecular diagnosis.

Child↗
PubMed1993

Exercise intolerance and recurrent myoglobinuria as the only expression of Xp21 Becker type muscular dystrophy.

A 9-year-old boy complained of exertional myalgias and described two episodes of myoglobinuria. His family history was negative for neuromuscular diseases. The findings of a neurological examination were normal. Serum creatine kinase was increased, ECG was normal, EMG showed slight "myopathic" signs. Muscle biopsy disclosed a small group of basophilic fibres as the only abnormality. Muscle glycolytic enzymes and carnitine palmitoyl transferase were normal. Immunoblotting using antidystrophin antibody demonstrated a protein with low molecular weight. Genomic DNA analysis showed a deletion of the HindIII fragments spanning from exon 45 to exon 48. Eight years after the first observation the patient has diffuse muscle hypertrophy without muscle weakness.

Biopsy↗
PubMed1992

A recombinant human 'mini'-hexokinase is catalytically active and regulated by hexose 6-phosphates.

Mammalian hexokinase type I is a 100 kDa enzyme that has been considered to be evolved from an ancestral 50 kDa yeast-type hexokinase, insensitive to product inhibition, by gene duplication and fusion. According to this model, and based on many experimental data, the catalytic site is associated with the C-terminal half of the enzyme, although an allosteric site for the binding of glucose 6-phosphate could be present on the N-terminal half of the molecule. We have isolated a cDNA clone of hexokinase from a lambda gt11 human placenta library comprising 2658 bp, containing a single open reading frame of 1893 nucleotides, which encodes a truncate form of hexokinase starting from asparagine-287 to the terminal serine-917. This clone was further digested with restriction enzyme NcoI to obtain almost only the C-terminal half of human hexokinase starting from methionine-455 to the terminal amino acid and was overexpressed in active form in Escherichia coli and purified by ion-exchange h.p.l.c. The overexpressed 'mini'-hexokinase was found not only to catalyse glucose phosphorylation, but also to be inhibited by glucose 6-phosphate and other mono- and bis-phosphate sugars exactly like the complete mammalian enzyme. These results suggest that the C-terminal half of human hexokinase, in addition to the catalytic site, also contains the regulatory site and that the evolutionary relationship between the hexokinases should be reconsidered by including the appearance of a regulatory site before the gene duplication.

Amino Acid Sequence↗
PubMed1992

Analysis of CA/GT microsatellite polymorphism in IVS8 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene: a study of Italian CF families.

Forty-six CF Italian patients and their parents were screened for a highly polymorphic microsatellite consisting of a variable number of CA/GT repeats in intron 8 of the CFTR gene. A strong degree of association was found between alleles 2 and 6 and the CF mutation delta F508. Moreover, considering the haplotypes at the closely linked locus D7S23 and the microsatellite's alleles, a strong linkage disequilibrium was again found for delta F508 and also for non-delta F508 CF chromosomes and the eight commonest haplotypes (B2, B6, C7, A6, A7, B7, D2 and D7). These data, compared with those described in the Spanish population, further support the common origin of the delta F508 mutation in Southern European populations.

Alleles↗
PubMed1992

Mapping of human hexokinase 1 gene to 10q11----qter.

Two partial-length cDNAs encoding the type 1 human hexokinase (ATP:D-hexose 6-phosphotransferase) were isolated from a placenta cDNA library using a 50-bp oligonucleotide synthesized according to the known sequence of human HK1. Using the larger (1.8 kb) cDNA insert as a probe and a panel of human-hamster somatic cell hybrids, we were able to assign the HK1 gene to the long arm of chromosome 10.

Animals↗
PubMed1991

Cloning and expression of a new human polypeptide which regulates protein phosphorylation in Escherichia coli.

A 1,820 bp full-length clone encoding for a new human protein was isolated from a lambda gt11 placental cDNA library using anti-human hexokinase antibodies. The cDNA complete sequence includes a 12 bp 5' non-coding region, a single open reading frame encoding a protein of 55 KDa (HP-10) and a 177 bp non-coding with two putative polyadenylation signals upstream of 3' poly(A)tail. The deduced amino acid sequence reveals a sequence of 492 amino acids that contains a stretch of 7 glutamic acid from position 169 and one potential glycosylation site at position 274. Although antibodies against hexokinase recognize the fusion protein and antibodies against the fusion protein recognize hexokinase, HP-10 is not human hexokinase, by a number of criteria including the alignment of determined amino acid sequences. In searching for a possible functional role of HP-10 its cDNA was inserted into a procaryotic vector which allows the expression of the non-fused protein. Bacteria expressing the HP-10 encoded protein were isolated and found to have a dramatic increase in endogenous phosphorylated proteins. Since HP-10 does not have a protein kinase activity per se it should be considered a new regulatory phosphorylation protein which is active in E. coli.

Amino Acid Sequence↗
PubMed1986

Cloning of the gene coding for human L apoferritin.

A recently reported cDNA clone coding for human promyelocytic L apoferritin, shows some differences with a liver L apoferritin cDNA. We have investigated if these differences are due to the expression of different genes or to an alternative transcription of an unique gene. In this paper we report data suggesting that a single gene is mainly expressed in several tissues examined. This gene has been cloned and characterized. Its sequence shows three introns: the exon sequence is identical to that of cDNA clone isolated from human liver. A minimum of five related pseudogenes have been also analysed. One of them is a processed pseudogene interrupted by an intron-like fragment.

Amino Acid Sequence↗