Induced recovery of defective membrane expression of a CC chemokine receptor 5 mutant by phytohemagglutinin

CC chemokine receptor 5 (CCR5) is a member of the G-protein-coupled receptor superfamily. It plays an important role in macrophage tropic human immunodeficiency virus-1 entry and in some inflammatory reactions. CCR5-893(–) is a single-nucleotide deletion that results in complete truncation of the C tail of the gene product. We detected CCR5-893(–) in a sample of patients infected with non-tuberculosis mycobacteria and found that it was maintained heterozygously with a frequency of 2%. There is no association between this mutation and any immunodeficiency. Membrane expression of CCR5-893(–) was substantially reduced compared to the wild type, but this defective surface presentation recovered greatly recovered in the presence of 2 mg l-1 phytohemagglutinin (PHA). However, PHA inducement did not affect the total intracellular expression of CCR5-893(–) or wild-type CCR5. Thus we suggest there exist some PHA-induced factor(s) that could mediate the presentation of truncated CCR5.Received 23 July 2003; accepted 18 August 2003     

Corticosteroidogenesis by isolated human adrenal cells: effect of serotonin and serotonin antagonists.

The direct effect of serotonin and antiserotonin agents on adrenal steroid biosynthesis was studied in isolated adrenal cells derived from patients with Cushing's syndrome. The results indicate that serotonin increases corticosterone production, while the serotonin antagonists cyproheptadine and methysergide depress adrenal steroid - particularly cortisol and aldosterone - biosynthesis.     

Levels of alpha1-antitrypsin in the spring and autumn seasons.

In a group of 84 pairs of 11-year-old children of both sexes, the level of the alpha1-antitrypsin (alpha1-AT) were ascertained in the autumn and spring. Although the mean levels of alpha1-AT in the two seasons hardly differed, the highly significant seasonal changes in the distribution curves of alpha1-AT values were noted in boys, whereas the levels showed higher stability in girls.     

CEP152 is a genome maintenance protein disrupted in Seckel syndrome

Functional impairment of DNA damage response pathways leads to increased genomic instability. Here we describe the centrosomal protein CEP152 as a new regulator of genomic integrity and cellular response to DNA damage. Using homozygosity mapping and exome sequencing, we identified CEP152 mutations in Seckel syndrome and showed that impaired CEP152 function leads to accumulation of genomic defects resulting from replicative stress through enhanced activation of ATM signaling and increased H2AX phosphorylation.     

Lack of long-term cortical reorganization after macaque retinal lesions

Several aspects of cortical organization are thought to remain plastic into adulthood, allowing cortical sensorimotor maps to be modified continuously by experience. This dynamic nature of cortical circuitry is important for learning, as well as for repair after injury to the nervous system. Electrophysiology studies suggest that adult macaque primary visual cortex (V1) undergoes large-scale reorganization within a few months after retinal lesioning, but this issue has not been conclusively settled. Here we applied the technique of functional magnetic resonance imaging (fMRI) to detect changes in the cortical topography of macaque area V1 after binocular retinal lesions. fMRI allows non-invasive, in vivo, long-term monitoring of cortical activity with a wide field of view, sampling signals from multiple neurons per unit cortical area. We show that, in contrast with previous studies, adult macaque V1 does not approach normal responsivity during 7.5 months of follow-up after retinal lesions, and its topography does not change. Electrophysiology experiments corroborated the fMRI results. This indicates that adult macaque V1 has limited potential for reorganization in the months following retinal injury.     

嵌段聚醚酯化物的结构分析

本文对合成的嵌段聚醚酯化物的分子结构做了红外、高压液相色谱和~(13)C核磁共振分析,得出其构象和各种原子连接的方式,这些特征图谱为研究和生产此类型表面活性剂提供了可靠的检测依据。     

Structure of mitochondrial ADP/ATP carrier in complex with carboxyatractyloside

ATP, the principal energy currency of the cell, fuels most biosynthetic reactions in the cytoplasm by its hydrolysis into ADP and inorganic phosphate. Because resynthesis of ATP occurs in the mitochondrial matrix, ATP is exported into the cytoplasm while ADP is imported into the matrix. The exchange is accomplished by a single protein, the ADP/ATP carrier. Here we have solved the bovine carrier structure at a resolution of 2.2 A by X-ray crystallography in complex with an inhibitor, carboxyatractyloside. Six alpha-helices form a compact transmembrane domain, which, at the surface towards the space between inner and outer mitochondrial membranes, reveals a deep depression. At its bottom, a hexapeptide carrying the signature of nucleotide carriers (RRRMMM) is located. Our structure, together with earlier biochemical results, suggests that transport substrates bind to the bottom of the cavity and that translocation results from a transient transition from a 'pit' to a 'channel' conformation.     

Recessive Robinow syndrome, allelic to dominant brachydactyly type B, is caused by mutation of ROR2

The autosomal recessive form of Robinow syndrome (RRS; MIM 268310) is a severe skeletal dysplasia with generalized limb bone shortening, segmental defects of the spine, brachydactyly and a dysmorphic facial appearance. We previously mapped the gene mutated in RRS to chromosome 9q22 (ref. 4), a region that overlaps the locus for autosomal dominant brachydactyly type B (refs 5,6). The recent identification of ROR2, encoding an orphan receptor tyrosine kinase, as the gene mutated in brachydactyly type B (BDB1; ref. 7) and the mesomelic dwarfing in mice homozygous for a lacZ and/or a neo insertion into Ror2 (refs 8,9) made this gene a candidate for RRS. Here we report homozygous missense mutations in both intracellular and extracellular domains of ROR2 in affected individuals from 3 unrelated consanguineous families, and a nonsense mutation that removes the tyrosine kinase domain and all subsequent 3' regions of the gene in 14 patients from 7 families from Oman. The nature of these mutations suggests that RRS is caused by loss of ROR2 activity. The identification of mutations in three distinct domains (containing Frizzled-like, kringle and tyrosine kinase motifs) indicates that these are all essential for ROR2 function.