Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The inactive X (Xi) differs from its active homologue (Xa) in a number of ways, including increased methylation of CpG islands, replication late in S phase, underacetylation of histone H4 and association with XIST RNA. Global changes in DNA methylation occur relatively late in development, but the other properties all change during or shortly after the establishment of Xi and may play a role in the mechanism by which an inactive chromatin conformation spreads across most of the chromosome. In the present report, we use two human X;autosome translocation chromosomes to study the spreading of inactive X chromatin across X;autosome boundaries. In one of these chromosomes, t(X;6), Xp distal to p11.2 is replaced by 6p21.1-6pter and, in the other, ins(X;16), a small fragment derived from 16p13 is inserted into the distal third of Xq. In lymphoid cells from patients carrying these translocations in an unbalanced form, Xi was shown by HUMARA assay to be derived exclusively [t(X:6)] or predominantly [ins (X;16)] from the derived X chromosome. We used a combination of immunolabelling and RNA/DNA fluorescence in situ hybridization to define the distribution of XIST RNA, deacetylated H4 and late-replicating DNA across the two derived X chromosomes in inactive form. Within the limits of the cytogenetic techniques employed, the results show complete coincidence of these three parameters, with all three being excluded from the autosomal component of the derived X chromosome.
Hum Mol Genet 1999 Feb
PMID:H4 acetylation, XIST RNA and replication timing are coincident and define x;autosome boundaries in two abnormal X chromosomes. 993 47

Premature ovarian failure (POF) is characterized by hypergonadotropic hypogonadism and amenorrhea before the age of 40. The condition has a heterogeneous background but genetic factors are demonstrated by the occurrence of familial cases. We identified a mother and daughter with POF both of whom carry an X;autosome translocation [t(X;11)(q24;q13)]. RNA expression studies of genes flanking the X-chromosome breakpoint revealed that both patients have reduced expression levels of the gene Progesterone Receptor Membrane Component-1 (PGRMC1). Mutation screening of 67 females with idiopathic POF identified a third patient with a missense mutation (H165R) located in the cytochrome b5 domain of PGRMC1. PGRMC1 mediates the anti-apoptotic action of progesterone in ovarian cells and it acts as a positive regulator of several cytochrome P450 (CYP)-catalyzed reactions. The CYPs are critical for intracellular sterol metabolism, including biosynthesis of steroid hormones. We show that the H165R mutation associated with POF abolishes the binding of cytochrome P450 7A1 (CYP7A1) to PGRMC1. In addition, the missense mutation attenuates PGRMC1's ability to mediate the anti-apoptotic action of progesterone in ovarian cells. These findings suggest that mutant or reduced levels of PGMRC1 may cause POF through impaired activation of the microsomal cytochrome P450 and increased apoptosis of ovarian cells.
Hum Mol Genet 2008 Dec 01
PMID:Alterations in the expression, structure and function of progesterone receptor membrane component-1 (PGRMC1) in premature ovarian failure. 1878 52

We report on a female patient with severe infantile spasms, profound global developmental arrest, hypsarrhythmia and severe mental retardation, associated with a de novo apparently balanced X;autosome translocation. Her neurological phenotype resembles that of X-linked infantile spasms (ISSX). Molecular study showed that the translocation disrupts a transcript involved in GTPases signalling, IQSEC2, mapped to the Xp11.22 region. Several genes involved in intracellular signalling pathways via Ras-homologous small GTPase have been implicated in X-linked neurological disorders. Expression studies revealed that the murine homolog of this transcript, Iqsec2, is highly expressed in the nervous system from the early stages of development. These data suggest that IQSEC2 could be considered a candidate gene for X-linked neurological disorders.
Mol Med Rep
PMID:Disruption of the IQSEC2 transcript in a female with X;autosome translocation t(X;20)(p11.2;q11.2) and a phenotype resembling X-linked infantile spasms (ISSX) syndrome. 2147 74