RNA-protein interactions within the 3 ' untranslated region of vimentin mRNA

Several functions have been attributed to protein binding within the 3'untranslated region (3'UTR) of mRNA, including mRNA localization, stability, and translational repression. Vimentin is an intermediate filament protein whose 3'untranslated sequence is highly conserved between species. In order to identify sequences that might play a role in vimentin mRNA function, we synthesized32P-labeled RNA from different regions of vimentin's 3'UTR and assayed for protein binding with HeLa extracts using band shift assays. Sequences required for binding are contained within a region 61-114 nucleotides downstream of the stop codon, a region which is highly conserved from Xenopus to man. As judged by competition assays, binding is specific. Solution probing studies of 32P-labeled RNA with various nucleases and lead support a complex stem and loop structure for this region. Finally, UV cross-linking of the RNA-protein complex identifies an RNA binding protein of 46 kDa. Fractionation of a HeLa extract on a sizing column suggests that in addition to the 46 kDa protein, larger complexes containing additional protein(s) can be identified. Vimentin mRNA has been shown to be localized to the perinuclear region of the cytoplasm, possibly at sites of intermediate filament assembly. To date, all sequences required for localization of various mRNAs have been confined to the 3'UTR. Therefore, we hypothesize that this region and associated protein(s) might be important for vimentin mRNA function such as in localization.     

Sex differences in olfactory identification and Wisconsin Card Sorting performance in schizophrenia: relationship to attention and verbal ability

We investigated the hypothesis that different prefrontal brain systems (i.e., dorsal vs. ventral) and sex contribute differentially to cognitive deficit in schizophrenia. Performance was assessed among clinically stable, chronic schizophrenic outpatients and matched normal control subjects on olfactory identification [on the University of Pennsylvania Smell Identification Test (UPSIT)] and on executive functions [using the Wisconsin Card Sorting Test (WCST)]. Patients were impaired on both tests compared to controls, and male schizophrenics were impaired on the WCST compared to female schizophrenics. The pattern of results suggests that gender differences on the UPSIT are mildly accentuated in schizophrenia. The data support our previous study indicating that UPSIT performance is largely independent of the executive or attentional deficits typically associated with schizophrenia, with the exception of verbal ability. Further research with larger samples is required to test the hypothesis that there is a severely impaired subgroup of male patients with diffuse prefrontal dysfunctions.     

Overview of the Mars Pathfinder mission and assessment of landing site predictions

Chemical analyses returned by Mars Pathfinder indicate that some rocks may be high in silica, implying differentiated parent materials. Rounded pebbles and cobbles and a possible conglomerate suggest fluvial processes that imply liquid water in equilibrium with the atmosphere and thus a warmer and wetter past. The moment of inertia indicates a central metallic core of 1300 to 2000 kilometers in radius. Composite airborne dust particles appear magnetized by freeze-dried maghemite stain or cement that may have been leached from crustal materials by an active hydrologic cycle. Remote-sensing data at a scale of generally greater than approximately 1 kilometer and an Earth analog correctly predicted a rocky plain safe for landing and roving with a variety of rocks deposited by catastrophic floods that are relatively dust-free.