Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polynucleotide kinase (ATP:5'-dephosphopolynucleotide 5'-phosphotransferase, EC 2.7.1.78) has been purified approx. 1500-fold from calf thymus. This enzyme phosphorylates 5'-hydroxyl termini in DNA using ATP as phosphate donor. RNA is phosphorylated at a much lower rate than DNA. The reaction requires the presence of a divalent cation, preferably Mg2+ or Mn2+ and is sensitive to sulfhydryl antagonists. The optimum pH for enzyme activity is 5.5. Enzyme activity is inhibited by low concentrations of inorganic sulfate and by some sulfate polymers. The kinase-catalyzed incorporation of the terminal phosphate of ATP into polynucleotides is inhibited by other nucleoside and deoxynucleoside triphosphates. The enzyme molecule has a molecular weight of about 70 000 and a Stokes radius of 4.3 nm. It has a frictional ratio of 1.44 indicating an asymmetrical structure. Calf thymus tissue should provide a useful alternative source for preparation of mammalian polynucleotide kinase.
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PMID:Purification and properties of polynucleotide kinase of calf thymus. 2 43

A purification procedure for RNA polymerase from uninfected and phage SP01-infected Bacillus subtilis is presented. The RNA polymerase purified from B. subtilis 10 min after infection with wild type phage SP01 is resolved into two major fractions (B, C) and one minor fraction (A) by calf thymus DNA-cellulose chromatography. Fraction C is indistinguishable from RNA polymerase from uninfected cells with respect to transcription specificity (both before and after phosphocellulose chromatography). Fraction B yields, on subsequent phosphocellulose chromatography, an enzyme (B-P) whose properties distinguish it from the host RNA polymerase. Enzyme B-P preferentially transcribes SP01 DNA and selectively forms rapidly initiating complexes with SP01 DNA but not with heterologous DNA. The SP01 RNA synthesized by Enzyme B-P includes, as previously reported, a large proportion of asymmetrical middle viral RNA. Host RNA polymerase holoenzyme synthesizes asymmetrical early viral RNA, while host core polymerase synthesizes symmetrical RNA that is complementary to early, middle, and late in vivo viral RNA and contains a preponderance of antimessenger. The subunit composition of Enzyme B-P is identical to host core polymerase with respect to the beta,beta', and alpha subunits and two additional components of mr equals 9,500 and 11,000 that we observe in all preparations of RNA polymerase. In addition, Enzyme B-P has two subunits of mr equals 13,000 and 28,000, which are synthesized after phage infection. On heterologous template, Enzyme B-P and host core polymerase have comparable activities. On these templates, addition of host initiation factor, sigma, restores full activity to Enzyme B-P as well as to host core polymerase. Sigma also modifies the activity of Enzyme B-P on SP01 DNA, restoring some asymmetrical early RNA transcription while retaining some asymmetrical middle RNA transcription.
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PMID:RNA polymerase from phage SP01-infected and uninfected Bacillus subtilis. 80 88

Structural chromosome aberrations were evaluated in peripheral blood samples obtained from three populations exposed to partial-body irradiation. These included 143 persons who received radiotherapy for enlarged thymus glands during infancy and 50 sibling controls; 79 persons irradiated for enlarged tonsils and 81 persons surgically treated for the same condition during childhood; and 77 women frequently exposed as young adults to fluoroscopic chest X rays during lung collapse treatment for tuberculosis (TB) and 66 women of similar ages treated for TB with other therapies. Radiation exposures occurred 30 and more years before blood was drawn. Doses to active bone marrow averaged over the entire body were 21, 6, and 14 cGy for the exposed thymic, tonsil, and TB subjects, respectively. Two hundred metaphases were scored for each subject, and the frequencies of symmetrical (stable) and asymmetrical (unstable) chromosome aberrations were quantified in 97,200 metaphases. Cells with stable aberrations were detected with greater frequency in the irradiated subjects compared with nonirradiated subjects in all three populations, and an overall test for an association between stable aberrations and partial-body ionizing radiation was highly significant (P less than 0.001). We found no evidence that radiation-induced aberrations varied by age at exposure. These data show that exposure of children or young adults to partial-body fractionated radiation can result in detectable increased frequencies of stable chromosome aberrations in circulating lymphocytes 30 years later, and that these aberrations appear to be informative as biological markers of population exposure.
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PMID:Chromosome aberrations in relation to radiation dose following partial-body exposures in three populations. 237 85

The developing thymus in Xenopus was examined at four different levels: 1) precursor immigration of cytogenetically distinct embryonic stem cells; 2) waves of colonization during tadpole life and metamorphosis; 3) inter-thymic exchange of cells between separate lobes; and 4) development of cortical and medullary thymocytes. Based on the flow cytometric analysis of cytogenetically distinct thymocytes, there were at least two periods of stem cell immigration into the thymus, one during early larval life and the second before or during metamorphosis. Within the thymus, cohorts of cells derived from the first wave of immigration expanded at different times. The initial expansion occurred before 35 days of development. Cells involved in the second period of expansion were also derived from the initial immigrants, expanded after 35 days, and resulted in a turnover of thymocytes during the larval period. Precursor cells entering the thymus during metamorphosis expanded and resulted in an additional replacement of thymocytes. Cortical and medullary thymocytes were isolated from animals that received embryonic stem cell grafts. No differences in the presence or absence, or in the percentages, of donor thymocytes in these different fractions were observed. When limiting numbers of stem cells were transplanted, several cases of asymmetrical thymic lobe colonization were observed. These data suggested that an inter-thymic exchange of cells did not occur during larval life.
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PMID:Precursor immigration and thymocyte succession during larval development and metamorphosis in Xenopus. 278 26

Thymus development and T cell differentiation were studied in mouse chimaeras produced by aggregating pre-implantation embryos of thymus-deficient nude BALB/c (nu/nu) and wild-type C57BL/6 (+/+) mice and vice versa. Chimaeras showed mosaic distribution of skin and coat pigmentation, of hair follicles, of glucosephosphate isomerase within all tested organs and of lymphocytes expressing the different major transplantation antigens (H-2). When tested for their capacity to generate vaccinia virus-specific and self-H-2 specific cytotoxic T cells, all chimaeras of BALB/c (nu/nu) H-2d in equilibrium C57BL/6 (+/+) H-2b type generated T cells of one or both parental origins that were specific for virus and for self-H-2 of the +/+ (H-2b) type only. In contrast, some BALB/c (+/+) H-2d in equilibrium C57BL/6 (nu/nu) H-2b chimaeras generated vaccinia virus-specific cytotoxic T cells specific for either H-2d (+/+) type or for H-2b (nu/nu) type. These asymmetrical results can be interpreted to indicate the following: (i) The +/+ thymus part alone is functional, but because of asymmetrical cross-reactivities of anti-self-H-2 specificities, the observed T cell restriction phenotypes differ. (ii) Both nu/nu and +/+ thymus parts are functional but immune response defects may be exaggerated in such chimaeras producing unexpected non-responsiveness to vaccinia virus linked to H-2d in H-2b (+/+) in equilibrium H-2d (nu/nu).
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PMID:Thymus differentiation and T-cell specificity in nu/nu +/+ mouse aggregation chimaeras. 660 49

An adenosine(5')tetraphospho(5')adenosine (Ap4A) binding protein has been purified from calf thymus. The protein is comprised of a single polypeptide of Mr 54000 and is capable of high-affinity (Kd = 13 microM) binding of Ap4A with great substrate specificity. The Ap4A binding protein has been isolated in two forms: a 'free', or non-polymerase-bound, form which predominates, and a similar form which copurifies with DNA polymerase alpha, but which can be resolved from it. The free form of Ap4A binding protein contains associated adenosine(5')tetraphospho(5')adenosine phosphohydrolase (Ap4Aase) activity, while the form resolved from DNA polymerase alpha contains no such activity. The Ap4Aase activity, which catalyzes the phosphohydrolysis of Ap4A to ATP and AMP, is strongly inhibited by low levels (50-100 microM) of Zn2+ without any effect on the Ap4A binding protein activity. This difference in associated Ap4Aase activity between free and polymerase-bound forms of the protein, plus the copurification mentioned above, indicate a specific association between Ap4A binding protein and DNA polymerase alpha.
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PMID:Adenosine(5')tetraphospho(5')adenosine-binding protein of calf thymus. 669 19

Dinucleosomes purified from micrococcal nuclease digests of steer kidney nuclei were stripped of H1 histone by exposure to 0.50 M NaCl. They were then formed in a complex with individual subfractions of calf thymus H1 histone by dialysis of histone-dinucleosome mixtures from 0.50 M NaCl to concentrations of NaCl between 0 M and 0.08 M; between 0.30 M and 0.10 M the complexes precipitated, and so were not included in the study. The presence of H1 in the complexes was shown to cause an asymmetrical, ordered condensation as revealed by distortions of the circular dichroic spectrum of the DNA. The distortions were negligible at 0.04 M NaCl and below, and increased as a function of ionic strength between 0.05 M and 0.08 M. The degree of distortion of the spectrum, and therefore the nature of dinucleosome condensation, differed greatly from one H1 subfraction to the next. One of the three subfractions tested had almost no effect on the circular dichroism in comparing its dinucleosome complex to H1-depleted dinucleosomes. The other subfractions to different degrees produced large distortions that resulted in spectra that were of the psi type at the higher salt concentration.
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PMID:Condensation of dinucleosomes by individual subfractions of H1 histone. 727 70

To evaluate contributions of catecholamines to inhibition of growth during chronic hypoxemia or severe undernutrition, epinephrine (Epi; 0.25-0.35 microg . kg-1 . min-1) or norepinephrine (NE; 0.5-0.7 microg . kg-1 . min-1) was administered to normoxemic fetuses in twin-pregnant ewes for 8-12 days, from 125 to 127 days of gestation. Both had similar effects and decreased fetal weight by approximately 20% relative to control twins (P < 0.01). Weight gain ceased during infusion of Epi or NE (-21 +/- 14.8 or 14 +/- 20.9 g/day), whereas controls gained 93 +/- 13.2 g/day (P < 0.01). Effects on tissues and organs varied, spleen and thymus being most retarded, whereas brain weight and skeletal measures were affected little. Selected muscles from infused fetuses weighed 72% of those in controls. Growth ceased during infusion (P < 0.001). Weight gain of hindlimb bones was negligible, but length increased at 56% of control rates. Arterial blood CO2 and plasma insulin were decreased (P < 0.001), but plasma glucose, growth hormone, and blood oxygenation increased (P < 0.001). Actions of Epi and NE could underlie asymmetrical growth retardation occurring in many adverse physiological situations during fetal development.
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PMID:Catecholamines inhibit growth in fetal sheep in the absence of hypoxemia. 960 6

We have studied the capability of the mouse thymus for asymmetrical formation. Concanavalin A (Con A)-stimulated proliferation of thymocytes from the right and left lobes of the thymus appeared to be significantly different. The direction of the differences depends on the dominance of the brain hemispheres with regard to motor asymmetry. In mice with right-dominant hemispheres, thymocytes from the left lobe of the thymus demonstrate a higher level of Con A-stimulated proliferation than those from the right lobe. In mice with left-dominant hemispheres, we found the opposite dependence. The in vivo experiments showed that the properties of cells from the contralateral lobes of the thymus proved to be a deciding factor that defines the differences at the level of the immune response in recipient mice with left-dominant hemispheres. This effect was less pronounced in mice with right-dominant hemispheres. Further analysis showed that left and right-dominant hemisphere mice differ according to the immune response only if mice from both groups received cells from the left but not from the right lobe of the thymus. That is, in the formation of the immune response to sheep red blood cells, the functional asymmetry of both the brain and thymus is of great importance. The experiments show that brain hemispheres and cells from different lobes of the thymus are able to interact in the regulatory effect on the immune response. The injection of cells from the thymus lobe ipsilateral to the dominant hemisphere, results in a significant excess of the immune response in left-dominant hemisphere mice in comparison with the response of right-dominant hemisphere mice. It can be concluded that this work demonstrates, for the first time, the asymmetrical function of a bilateral immune organ--the thymus. The asymmetry is shown not only at the level of Con A-induced proliferative activity but also at the level of the influence on the humoral T-dependent immune response in mice. Besides, we have found the interaction of brain hemispheres and thymus lobes in the regulation of the immune response.
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PMID:Functional asymmetry of thymus and the immune response in mice. 1184 84

Lesser forms of incomplete cleft lip (CL) have been called microform, occult, forme fruste, and congenitally healed. The association of a minimal bilateral CL in branchio-oculo-facial syndrome (BOFS) is well described and commonly referred to as a "pseudocleft." We conducted a systematic analysis of CL types in BOFS, including a retrospective cross-sectional chart and photographic review with variable longitudinal follow-up of our patients and those described in the literature. We compared data on the type of CL and palate (CL/P) and craniofacial and extracranial anomalies in patients with BOFS and classified the lesser forms CL as either minor-form, microform, or mini-microform as defined by the extent of disruption at the vermilion-cutaneous junction. The study comprised 62 patients with BOFS (1 new and 61 in literature, 4 treated by J.B.M). Forty-four patients (71%) had CL only; 16 (26%) had CL/P; and 2 patients had neither CL nor isolated CP. Thirty-five patients with CL had adequate information for analysis (defined as either seen by J.B.M., having a published photograph, or having a detailed description). The most common type was bilateral symmetrical, lesser form CL (n = 20): minor-form (n = 2), microform (n = 6), or mini-microform (n = 12). Among 17 asymmetrical forms, the left side was more severely affected side than the right (12 vs 5). Of 9 patients with CL/P and adequate clinical description, 4 were bilaterally symmetrically complete. Other anomalies, in addition to the familiar cardinal features of BOFS, included facial nerve weakness (n = 6), chin dimple or cleft of the lower lip (n = 4), upper labial pits (n = 6), minor digital anomalies (n = 12), renal anomalies (n = 14), and ectopic thymus (n = 18). This analysis reaffirms the high frequency of CL or CL/P in BOFS and the rarity of isolated cleft palate and underscores that the term "pseudocleft" lip is incorrect. The more precise lesser form designations used in this study may prove useful for future clinical studies because the causative gene, TFAP2A, is known. Lesser forms of CL may be the most subtle expression of BOFS and assist in identifying patients. Unlike major forms of CL/P, either, syndromic or non syndromic, lesser forms suggest that the developmental insult occurs later in labial formation when fusion of the medial nasal process and maxillary process is nearly complete. The deficient vermilion-mucosa and hypoplastic orbicularis oris may be the result of incomplete or deficient mesodermal penetration of the ectodermal envelope. Another possible pathogenic explanation is that failure of labial closure occurs earlier than in a major cleft when the primitive cells of ectoderm and mesoderm retain the capacity to "heal" the defect.
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PMID:Lesser forms of cleft lip associated with the branchio-oculo-facial syndrome. 1979 28


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