PHF10 is a mammalian homologue of SAYP whose expression is confined to certain tissues in adults. The molecular mechanism of the SAYP function is related to the conserved domain SAY, which assembles a nuclear supercomplex BTFly consisting of Brahma and TFIID coactivators. We suggest that nuclear supercomplexes may be important means of gene-specific regulation of transcription during development.”
“The mechanisms by which agonists and other ligands bind ligand-gated
ion channels are important determinants of function in neurotransmitter receptors. The partial agonist, kainic acid (KA) activates a less desensitized, and more robust AMPA receptor (AMPAR) current than full agonists, glutamate or AMPA. Cyclothiazide (CTZ), the allosteric modulator of
AMPARs, potentiates receptor currents by inhibiting receptor desensitization resulting from agonist activation. We have constructed an AMPAR GluR1 subunit deletion mutant Selleckchem Bafilomycin A1 GluR1L3T(Delta 739-784) by deleting the splice-variable “flip/flop” region of the L3 domain in the wild-type receptor and compared its function to that of the wild-type GluR1 receptor and an AMPAR substitution mutant GluR1A782N. When compared to GluR1, the potency of glutamate activation of GluR1L3T was increased, in contrast to a decrease in potency of activation and reduced sensitivity to optimal concentrations of KA. Furthermore, GluR1L3T was totally insensitive to CTZ potentiation of KA and glutamate-activated currents in Xenopus laevis C59 Wnt mouse oocytes. The potency of glutamate and KA activation of GluR1A782N was not significantly different from that of the wild-type GluR1 receptor although Batimastat cell line the mutant receptor currents were more sensitive to CTZ potentiation than the wild-type receptor current. This result is an indication that glutamate and KA binding to the agonist (S1/S2) domain on AMPAR can be modulated by an expendable splice-variable region of the receptor. Moreover, the effect of the allosteric modulator, CTZ on agonist activation of AMPAR can also be modified by a non-conserved amino acid residue substitution within the splice-variable “flip/flop” region. (C) 2008 Elsevier B.V.
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“Plants produce structurally diverse triterpenoids, which are important for their life and survival. Most triterpenoids and sterols share a common biosynthetic intermediate, 2,3-oxidosqualene (OS), which is cyclized by 2,3-oxidosqualene cyclase (OSC). To investigate the role of an OSC, marneral synthase 1 (MRN1), in planta, we characterized a Arabidopsis mrn1 knock-out mutant displaying round-shaped leaves, late flowering, and delayed embryogenesis. Reduced growth of mrn1 was caused by inhibition of cell expansion and elongation. Marnerol, a reduced form of marneral, was detected in Arabidopsis overexpressing MRN1, but not in the wild type or mrn1. Alterations in the levels of sterols and triterpenols and defects in membrane integrity and permeability were observed in the mrn1.