Overexpression of HuR, a nuclear-cytoplasmic shuttling protein, increases the in vivo stability of ARE-containing mRNAs

The messenger RNAs of many proto-oncogenes, cytokines and lymphokines are targeted for rapid degradation through AU-rich elements (AREs) located in their 3' untranslated regions (UTRs). HuR, a ubiquitously expressed member of the Elav family of RNA binding proteins, exhibits specific affinities for ARE-containing RNA sequences in vitro which correlate with their in vivo decay rates, thereby implicating HuR in the ARE-mediated degradation pathway. We have transiently transfected HuR into mouse L929 cells and observed that overexpression of HuR enhances the stability of beta-globin reporter mRNAs containing either class I or class II AREs. The increase in mRNA stability parallels the level of HuR overexpression, establishing an in vivo role for HuR in mRNA decay. Furthermore, overexpression of HuR deletion mutants lacking RNA recognition motif 3 (RRM 3) does not exert a stabilizing effect, indicating that RRM 3 is important for HuR function. We have also developed polyclonal anti-HuR antibodies. Immunofluorescent staining of HeLa and L929 cells using affinity-purified anti-HuR antibody shows that both endogenous and overexpressed HuR proteins are localized in the nucleus. By forming HeLa-L929 cell heterokaryons, we demonstrate that HuR shuttles between the nucleus and cytoplasm. Thus, HuR may initially bind to ARE-containing mRNAs in the nucleus and provide protection during and after their export to the cytoplasmic compartment.     

HuR, a novel target of anti-Hu antibodies, is expressed in non-neural tissues

Paraneoplastic encephalomyelitis (PEM) is characterized by a diverse set of clinical signs that are limited to the nervous system. The serologic hallmark of PEM is the presence of circulating autoantibodies, collectively referred to as 'anti-Hu,' which immunoreact specifically with members of the Elav protein family. Until recently, the ELAV antigens were only detected in neurons, thus strongly supporting a role for anti-Hu antibodies in the selective neural tissue injury in PEM. The identification of HuR, however, a new member with a broad, non-neural pattern of RNA expression, raises several fundamental questions regarding PEM. First, why are non-neural tissues spared in PEM? Second, why is PEM predominantly associated with neuroendocrine tumors? To begin addressing these questions, we sought to determine whether the antibody response to HuR differs from the neural-specific counterparts in patients with PEM, and to characterize the protein expression pattern of this novel antigen in peripheral tissues and tumors. Using sera from 11 patients with Hu-positive PEM, we found that the majority of samples (73%) were weakly or non-reactive for recombinant HuR on Western blot, in contrast to consistently strong immunoreactivity with the neural-specific members HuD and Hel-N1. We also demonstrate that HuR is expressed at the protein level in both non-neural tissues and non-neuroendocrine tumors. These findings suggest that immunoreactive differences among Elav family members may contribute to the neural-restrictive pattern of tissue injury in patients with PEM.     

Characterization of IS1515, a functional insertion sequence in Streptococcus pneumoniae

Several BRCA2 mutations are found to occur in geographically diverse breast and ovarian cancer families. To investigate both mutation origin and mutation-specific phenotypes due to BRCA2, we constructed a haplotype of 10 polymorphic short tandem-repeat (STR) markers flanking the BRCA2 locus, in a set of 111 breast or breast/ovarian cancer families selected for having one of nine recurrent BRCA2 mutations. Six of the individual mutations are estimated to have arisen 400-2,000 years ago. In particular, the 6174delT mutation, found in approximately 1% of individuals of Ashkenazi Jewish ancestry, was estimated to have arisen 29 generations ago (1-LOD support interval 22-38). This is substantially more recent than the estimated age of the BRCA1 185delAG mutation (46 generations), derived from our analogous study of BRCA1 mutations. In general, there was no evidence of multiple origins of identical BRCA2 mutations. Our study data were consistent with the previous report of a higher incidence of ovarian cancer in families with mutations in a 3.3-kb region of exon 11 (the ovarian cancer cluster region [OCCR]) (P=.10); but that higher incidence was not statistically significant. There was significant evidence that age at diagnosis of breast cancer varied by mutation (P<.001), although only 8% of the variance in age at diagnosis could be explained by the specific mutation, and there was no evidence of family-specific effects. When the age at diagnosis of the breast cancer cases was examined by OCCR, cases associated with mutations in the OCCR had a significantly older mean age at diagnosis than was seen in those outside this region (48 years vs. 42 years; P=.0005).     

Positive transfer from sequence production to sequence discrimination in a nonverbal organism.

Examined the relation between a pigeon's ability to produce and to recognize a particular arbitrary sequence of arbitrary elements, in 3 experiments involving a total of 100 naive male White Carneaux pigeons. In Exp I, 16 Ss were trained to discriminate sequences composed of 3 successively presented colors (A, B, and C). A yes response was rewarded for identifying A?→?B?→?C sequences; a no response for identifying non-A?→?B?→?C sequences. Exp II showed that the acquisition of this discrimination was facilitated by prior training on the production of the sequence A?→?B?→?C. Exp III showed that the facilitation of the discrimination of A?→?B?→?C sequences observed in Exp II could be attributed specifically to knowledge of the order of the elements A, B, and C that was acquired during the production of the sequence A?→?B?→?C. The control conditions of Exp III were (a) a pseudo-production task in which the Ss pecked the colors A, B, and C as presented successively; (b) a nonsequential task that established discriminative performance with respect to A, B, and C; (c) pseudo-production training that was preceded by discrimination training; and (d) training to produce either the sequence C?→?B?→?A or B?→?A?→?C. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of the striatum, cerebellum, and frontal lobes in the learning of a visuomotor sequence

This study was designed to examine the role of the striatum, cerebellum, and frontal lobes in the implicit learning of a visuomotor sequence. The performance of patients with idiopathic Parkinson's disease (PD), with damage to the cerebellum, or with a circumscribed lesion to the frontal lobes was thus compared to that of separate groups of matched normal control subjects on an adapted version of the Repeated Sequence Test. This paradigm consists of a visual reaction-time task with a fixed embedded sequence of finger movements to be performed based on presentation of visual stimuli. Subjects received four blocks of trials (i.e., 40 presentations of a 10-item sequence) per day over 6 training days. Following the last experimental session, subjects were also given two tests measuring their declarative knowledge of the sequence. Only PD patients with a bilateral striatal-dysfunction or patients with lesions to the cerebellum failed to improve their performance in the last three training sessions, hence suggesting an impairment late in the acquisition process. Further analyses revealed that such impairment was mainly implicit in nature, and that it could not be ascribed to a general decline in cognitive functioning, to mood disturbances, or to the severity of the motor symptoms. By contrast, the level of declarative knowledge of the sequence did not differ between the three clinical groups and their respective groups of normal subjects. These findings suggest that, unlike declarative memory, the incremental acquisition of a new visuomotor skill depends upon the integrity of both the striatum and the cerebellum, but not of the frontal lobes.     

Definition, distribution, and use of a conserved Bovidae retroposon element sequence motif

Based on a data-base search, the sequences of 32 Bovidae retroposon elements have been compared. Two conserved areas are identified, and one of the corresponding sequences of the derived bovine consensus was used to design oligonucleotides as primer molecules for random DNA amplification of Bovidae DNA. Such a primer binding site should occur on average every 10,000 bp in the bovine genome, as suggested by a survey of published sequences. This estimate about the distribution of these possible primer binding sites was experimentally substantiated by mapping four of these primer binding sites within 40 kb of contiguous bovine DNA, carrying the heretofore undescribed bovine lactoferrin gene. Furthermore, these conserved, ubiquitous sequence motifs prove to be useful for mapping of bovine DNA.     

Acquisition and extinction of a shuttling response in honeybees (Apis mellifera) as a function of the probability of reward.

The effects of partial (intermittent) vs consistent reward on the acquisition and extinction of a shuttling response were studied in 3 experiments with foraging honeybees. Adding nonrewarded trials to rewarded trials (the equated-reinforcements design) improved performance in acquisition and increased resistance to extinction. Substituting nonrewarded trials for some rewarded trials (the equated-trials design), which had little effect on acquisition, also increased resistance to extinction but to a lesser extent than adding nonrewarded trials. Marked variations in the schedule of partial reward (the sequence of rewarded and nonrewarded trials) were without effect. The results are compared with those of analogous experiments on vertebrates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amino-acid sequence of a cooperative, dimeric myoglobin from the gastropod mollusc, Buccinum undatum L

OBJECTIVE: The aim of this study to evaluate during normal pregnancy plasma bioavailable testosterone and androstanediol glucuronide levels. MEASUREMENTS: Bioavailable testosterone, androstanediol glucuronide and SHBG levels were evaluated every 4 weeks from week 6 to week 38 in 10 normal pregnant women. We also measured plasma oestradiol, oestriol, delta 4-androstenedione, 17-hydroxyprogesterone, progesterone and testosterone. RESULTS: The mean bioavailable testosterone levels were within the range of non-pregnant women but with an increasing trend until delivery. Androstanediol glucuronide had increased at weeks 6 and 8, decreased at week 14, remained low at week 30, and increased again at week 34. SHBG was significantly correlated with testosterone, oestradiol and oestriol. No correlation could be established between androstanediol glucuronide and any other parameter. DISCUSSION: Bioavailable testosterone (non-SHBG bound testosterone) represents the sum of free testosterone plus albumin bound testosterone. The increase in testosterone concentrations with decreased albumin levels during pregnancy, could suggest reduced metabolic clearance of testosterone throughout pregnancy. No correlation was established between the decrease in androstanediol glucuronide and increase in progesterone, suggesting that the decrease in androstanediol glucuronide is not a consequence of the inhibitory effect of progesterone on 5 alpha-reductase activity.     

Identification and sequence analysis of Treponema pallidum tprJ, a member of a polymorphic multigene family

This study examines occupational health and safety provision from farmers' perspectives, to address the question 'Are farmers' health and safety needs being met?' Given that farmers encounter a variety of health and safety risks in the course of their daily work, and that available statistics clearly indicate they are a high risk group, a review of the literature suggests that this area has attracted little research attention. No study has critically examined the system of occupational health and safety provision for farmers and no attempts have been made to elicit farmers' perspectives on the subject. A telephone survey using a questionnaire divided into four sections, involving a random sample of 150 farmers from the counties of Cumbria, Cheshire and Cambridgeshire in England, found that farmers considered the system of occupational health and safety provision to be inadequate and that their occupational health and safety needs were not being met. Recommendations for improvements are made based on the results of the survey.     

Formation and sequence analysis of secretoneurin, a neuropeptide derived from secretogranin II, in mammalian, bird, reptile, amphibian and fish brains

An anatomic study of the sacral dorsal root ganglia (DRG) was performed to determine the location and dimensions of the S1-4 DRGs and to correlate this information to sacral nerve root ganglion lesions. S1 DRGs were located in the intraforaminal region in 55-60% and in the intracanalar region in 40-45%. S2 DRGs were in the intraforaminal region in 15-50% and in the intracanalar region in 50-85%. All the S3 and S4 DRGs were located in the intracanalar region. None of the sacral DRGs was located in the extraforaminal region. The intraforaminal position of the S1 and S2 ganglia renders them vulnerable to compression caused by sacral fractures involving the sacral foramina because of the little space available for these ganglia in the foraminal region. The S1 DRG, with its its relatively larger dimensions and its intracanalar position relative to the other sacral DRGs, may be susceptible to compression by the L5-S1 disk herniation. Its intraforaminal position may predispose it to injury during S1 or S2 pedicle screw placement.     

Conserved sequence motifs among bacterial, eukaryotic, and archaeal phosphatases that define a new phosphohydrolase superfamily

Members of a new molecular family of bacterial nonspecific acid phosphatases (NSAPs), indicated as class C, were found to share significant sequence similarities to bacterial class B NSAPs and to some plant acid phosphatases, representing the first example of a family of bacterial NSAPs that has a relatively close eukaryotic counterpart. Despite the lack of an overall similarity, conserved sequence motifs were also identified among the above enzyme families (class B and class C bacterial NSAPs, and related plant phosphatases) and several other families of phosphohydrolases, including bacterial phosphoglycolate phosphatases, histidinol-phosphatase domains of the bacterial bifunctional enzymes imidazole-glycerolphosphate dehydratases, and bacterial, eukaryotic, and archaeal phosphoserine phosphatases and threalose-6-phosphatases. These conserved motifs are clustered within two domains, separated by a variable spacer region, according to the pattern [FILMAVT]-D-[ILFRMVY]-D-[GSNDE]-[TV]-[ILVAM]-[AT S VILMC]-X-?YFWHKR)-X-?YFWHNQ?-X( 102,191)-?KRHNQ?-G-D-?FYWHILVMC?-?QNH?-?FWYGP?-D -?PSNQYW?. The dephosphorylating activity common to all these proteins supports the definition of this phosphatase motif and the inclusion of these enzymes into a superfamily of phosphohydrolases that we propose to indicate as "DDDD" after the presence of the four invariant aspartate residues. Database searches retrieved various hypothetical proteins of unknown function containing this or similar motifs, for which a phosphohydrolase activity could be hypothesized.