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Kuang AA, Novak KD, Kang SM, Bruhn K, Lenardo MJ. Interaction between NF-kappa B- and serum response factor-binding elements activates an interleukin-2 receptor alpha-chain enhancer specifically in T lymphocytes. Mol Cell Biol 1993; 13:2536-45. [PMID: 8455627 PMCID: PMC359582 DOI: 10.1128/mcb.13.4.2536-2545.1993] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We find that a short enhancer element containing the NF-kappa B binding site from the interleukin-2 receptor alpha-chain gene (IL-2R alpha) is preferentially activated in T cells. The IL-2R alpha enhancer binds NF-kappa B poorly and is only weakly activated by the NF-kappa B site alone. Serum response factor (SRF) binds to a site adjacent to the NF-kappa B site in the IL-2R enhancer, and both sites together have strong transcriptional activity specifically in T cells. Surprisingly, the levels of SRF constitutively expressed in T cells are consistently higher than in other cell types. Overexpression of SRF in B cells causes the IL-2R enhancer to function as well as it does in T cells, suggesting that the high level of SRF binding in T cells is functionally important.
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102
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Kang SM, Beverly B, Tran AC, Brorson K, Schwartz RH, Lenardo MJ. Transactivation by AP-1 is a molecular target of T cell clonal anergy. Science 1992; 257:1134-8. [PMID: 1509265 DOI: 10.1126/science.257.5073.1134] [Citation(s) in RCA: 262] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Anergy is a mechanism of T lymphocyte tolerance induced by antigen receptor stimulation in the absence of co-stimulation. Anergic T cells were shown to have a defect in antigen-induced transcription of the interleukin-2 gene. Analysis of the promoter indicated that the transcription factor AP-1 and its corresponding cis element were specifically down-regulated. Exposure of anergic T cells to interleukin-2 restored both antigen responsiveness and activity of the AP-1 element.
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103
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Kang SM, Tsang W, Doll S, Scherle P, Ko HS, Tran AC, Lenardo MJ, Staudt LM. Induction of the POU domain transcription factor Oct-2 during T-cell activation by cognate antigen. Mol Cell Biol 1992; 12:3149-54. [PMID: 1620122 PMCID: PMC364529 DOI: 10.1128/mcb.12.7.3149-3154.1992] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Oct-2 is a transcription factor that binds specifically to octamer DNA motifs in the promoters of immunoglobulin and interleukin-2 genes. All tumor cell lines from the B-cell lineage and a few from the T-cell lineage express Oct-2. To address the role of Oct-2 in the T-cell lineage, we studied the expression of Oct-2 mRNA and protein in nontransformed human and mouse T cells. Oct-2 was found in CD4+ and CD8+ T cells prepared from human peripheral blood and in mouse lymph node T cells. In a T-cell clone specific for pigeon cytochrome c in the context of I-Ek, Oct-2 was induced by antigen stimulation, with the increase in Oct-2 protein seen first at 3 h after activation and continuing for at least 24 h. Oct-2 mRNA induction during antigen-driven T-cell activation was blocked by cyclosporin A, as well as by protein synthesis inhibitors. These results suggest that Oct-2 participates in transcriptional regulation during T-cell activation. The relatively delayed kinetics of Oct-2 induction suggests that Oct-2 mediates the changes in gene expression which occur many hours or days following antigen stimulation of T lymphocytes.
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104
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Kang SM, Tran AC, Grilli M, Lenardo MJ. NF-kappa B subunit regulation in nontransformed CD4+ T lymphocytes. Science 1992; 256:1452-6. [PMID: 1604322 DOI: 10.1126/science.1604322] [Citation(s) in RCA: 271] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Regulation of interleukin-2 (IL-2) gene expression by the p50 and p65 subunits of the DNA binding protein NF-kappa B was studied in nontransformed CD4+ T lymphocyte clones. A homodimeric complex of the NF-kappa B p50 subunit was found in resting T cells. The amount of p50-p50 complex decreased after full antigenic stimulation, whereas the amount of the NF-kappa B p50-p65 heterodimer was increased. Increased expression of the IL-2 gene and activity of the IL-2 kappa B DNA binding site correlated with a decrease in the p50-p50 complex. Overexpression of p50 repressed IL-2 promoter expression. The switch from p50-p50 to p50-p65 complexes depended on a protein that caused sequestration of the p50-p50 complex in the nucleus.
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105
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Beverly B, Kang SM, Lenardo MJ, Schwartz RH. Reversal of in vitro T cell clonal anergy by IL-2 stimulation. Int Immunol 1992; 4:661-71. [PMID: 1616898 DOI: 10.1093/intimm/4.6.661] [Citation(s) in RCA: 265] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Stimulation of a normal type I mouse T helper cell clone (TH1) with concanavalin A in the absence of antigen presenting cells (APC) in vitro results in the induction of a hyporesponsive state known as T cell clonal anergy. This state is characterized by a decrease in proliferation following stimulation with antigen and APC resulting from a decrease in the production of IL-2. Production of the lymphokines IL-3/granulocyte macrophage colony stimulating factor and IFN-gamma is also reduced, although to a lesser degree. Stimulation of such anergic cells with IL-2 results in proliferation and a complete reversal of the state. We demonstrate that this reversal is not due to the outgrowth of a subpopulation of cells that had escaped anergy induction, but rather occurs in all the cells. Anergy also dissipated spontaneously, although much more slowly, in the absence of T cell antigen receptor occupancy. Finally, we show that a similar state can be produced by normal activation with antigen and APC if IL-2 and other factors are removed at 16-20 h. These results indicate that the anergic state is not a permanent change in the TH1 cell. Anergy induction appears to be a consequence of the inability of the cell to divide extensively following stimulation through the antigen-specific receptor. We propose a model to explain these results in terms of a relatively stable negative regulatory factor.
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106
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Kang SM, Wohlrab F, Wells RD. Metal ions cause the isomerization of certain intramolecular triplexes. J Biol Chem 1992; 267:1259-64. [PMID: 1309767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The influence of cations on the capacity of five oligopurine.oligopyrimidine mirror repeat sequences to adopt intramolecular triplexes (the usual H-y3 isomer and/or the rare H-y5 isomer) in recombinant plasmids was investigated. Unexpectedly, the presence of certain metal ions (magnesium, zinc, manganese, and calcium) stabilized the (GAA)4TTCGC(GAA)4 insert in the rare H-y5 when cloned into either of two different sequence backgrounds. Alternatively, either shortening or lengthening the sequence at the central interruption, which becomes the loop of the triplex, led to the formation of the canonical H-y3 under all conditions tested. Similarly, other oligopurine.oligopyrimidine mirror repeat sequences (i.e. (GAA)8 or (GGA)8) formed only the H-y3 under all experimental conditions. All triplexes were stabilized by negative supercoiling at pH 5.0; chemical probe and primer extension analyses served as critical structural tools. Hence, the nature of the central interruption sequence (the loop) of the mirror repeat is important for the stabilization of the H-y5. This region may be important for metal ion binding in the initial stages of triplex formation and thus may play a critical role in determining which isomer is formed. The possible biological role of a DNA sequence adopting three different conformations is discussed.
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107
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Kang SM, Wohlrab F, Wells RD. Metal ions cause the isomerization of certain intramolecular triplexes. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)48423-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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108
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Brorson KA, Beverly B, Kang SM, Lenardo M, Schwartz RH. Transcriptional regulation of cytokine genes in nontransformed T cells. Apparent constitutive signals in run-on assays can be caused by repeat sequences. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1991; 147:3601-9. [PMID: 1940359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cytokines are immunoregulatory proteins that are secreted by T lymphocytes and other cells upon activation. A controversy exists as to whether the induction of cytokine production is mediated at the transcriptional level by the initiation of RNA synthesis or at the post-transcriptional level by the enhancement of mRNA stability. We show that in a nontransformed T cell clone the induction of all of the cytokines that are analyzed in this report is mediated transcriptionally. We also found that a constitutive signal was seen in resting cells when the probes used in the nuclear run-on assay contained some potential cross-hybridizing sequences, for example a poly (A) tract in a cDNA probe. This observation could explain the constitutive signals seen in other studies that claim cytokine production is regulated by differential mRNA stability.
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109
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Brorson KA, Beverly B, Kang SM, Lenardo M, Schwartz RH. Transcriptional regulation of cytokine genes in nontransformed T cells. Apparent constitutive signals in run-on assays can be caused by repeat sequences. THE JOURNAL OF IMMUNOLOGY 1991. [DOI: 10.4049/jimmunol.147.10.3601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Cytokines are immunoregulatory proteins that are secreted by T lymphocytes and other cells upon activation. A controversy exists as to whether the induction of cytokine production is mediated at the transcriptional level by the initiation of RNA synthesis or at the post-transcriptional level by the enhancement of mRNA stability. We show that in a nontransformed T cell clone the induction of all of the cytokines that are analyzed in this report is mediated transcriptionally. We also found that a constitutive signal was seen in resting cells when the probes used in the nuclear run-on assay contained some potential cross-hybridizing sequences, for example a poly (A) tract in a cDNA probe. This observation could explain the constitutive signals seen in other studies that claim cytokine production is regulated by differential mRNA stability.
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110
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Kang SM, Titus JS. Increased Proteolysis of Senescing Rice Leaves in the Presence of NaCl and KCl. PLANT PHYSIOLOGY 1989; 91:1232-7. [PMID: 16667137 PMCID: PMC1062145 DOI: 10.1104/pp.91.3.1232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
NaCl and KCl enhanced the degradation of chlorophylls and proteins in detached rice (Oryza sativa) leaves in a concentration-dependent manner. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) accounted for 73 to 80% of the protein lost by day 4 in the light. NaCl at 50 millimolar increased proteolysis by 21% over the control in 4 days, but the addition of cycloheximide reduced the increase to about one-half. Cycloheximide alone had no effect on proteolytic activity during this period. Leaf segments taken from 10-day-old seedlings contained the highest proteolytic activity. Both NaCl and KCl increased the activity of Rubisco-degrading endoproteinases (the amount of ninhydrin-positive compounds measured from HCl-hydrolyzates of trichloroacetic acid-soluble supernatant), but decreased the activity of hemoglobin- and Rubisco-degrading exoproteinases (the amount of ninhydrin-positive compounds measured directly from trichloroacetic acid-soluble supernatant). Efflux of amino acids from senescing leaf segments into the incubation media increased 7- and 12-fold in the presence of KCl and NaCl, respectively. The increased efflux resulted in a negative correlation between salt concentration and amino acid content of leaf segments at the later stage of senescence. It is concluded that, in addition to the induction of new proteinase synthesis, the increased efflux of protein hydrolyzates may play a significant role in increasing proteolysis of salt-treated leaves, especially at the later stages of senescence.
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111
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Eun HM, Kang Y, Kang SM, Bae YS, Yoon JW. An efficient and site-specific gene trimming method. Biotechniques 1989; 7:506-10. [PMID: 2699239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Trimming a DNA strand into a precisely determined fragment can be carried out efficiently by an improved method involving a site-specific trim-primer and a single-stranded DNA template which is generated from a multifunctional vector, pTZ18R, and linearized by using an Eco RI-pTZ18R splinter. A complementary DNA strand is synthesized by DNA polymerase I (Klenow), and the 3'-end of the template upstream from the annealed primer is trimmed by subsequent T4 DNA polymerase reaction. An ATG translation initiator codon or a termination codon can be incorporated into the trim-primer, providing versatility to this single-stranded DNA-initiated gene trimming method that can be applied to subcloning and expression of any DNA fragment with known terminal sequences.
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112
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Moon GJ, Kang SM. Inhibition of phytoagglutinin potency of Korean vicia unijuga by human urine. NIHON HOIGAKU ZASSHI = THE JAPANESE JOURNAL OF LEGAL MEDICINE 1989; 43:16-9. [PMID: 2770033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Human urines are often examined for individual identification in medicolegal field, therefore, authors attempted to classify the urines by inhibition of agglutination potency of phytoagglutinin Korean vicia unijuga which is known as a panphytoagglutinin to human red blood cells, and demonstrated that some individuals excrete urine which has ability to interfere with the agglutination potency of vicia extracts. The inhibiting substance appears to be either a protein or a glycoprotein, for it can be eliminated by boiling the urine sample. This substance is not present in human serum, semen and saliva. Presence or absence of the inhibiting substance in the urine has no relation to the individual's blood type and a sample urine spot test yielded a high rate of inhibitory property.
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113
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Tzeng CC, Tsai YJ, Tso HS, Kang SM, Chang CL. Effects of labetalol and lidocaine on B.P. and H.R. during laryngoscopy and endotracheal intubation. MA ZUI XUE ZA ZHI = ANAESTHESIOLOGICA SINICA 1988; 26:265-72. [PMID: 3231024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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114
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Kang SM, Ho WM, Chen YT, Tsao HS. Haemodynamic changes in cardiac surgical patients during induction of anesthesia with isoflurane, pancuronium and lidocaine. MA ZUI XUE ZA ZHI = ANAESTHESIOLOGICA SINICA 1986; 24:166-71. [PMID: 3796241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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115
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Angier RB, Citarella RV, Damiani M, Fabio PF, Fields TL, Kang SM, Lin Y, Lindh HF, Murdock KC, Petty SR. Synthesis of 3,6-bis(aminoalkoxy)acridines and their effect on the immune System. J Med Chem 1983; 26:1710-5. [PMID: 6644739 DOI: 10.1021/jm00366a010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A series of 3,6-bis(aminoalkoxy)acridines (2) was prepared and shown to have a protective antiviral effect against an interferon-sensitive virus (Columbia SK) and to partially restore an antibody response to a T-cell-dependent antigen in leukemic immunosuppressed mice. The presence of circulating interferon and the stimulation of natural killer cell activity in mice was observed for 21.
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116
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Kang SM, Matsui H, Titus JS. Characteristics and Activity Changes of Proteolytic Enzymes in Apple Leaves during Autumnal Senescence. PLANT PHYSIOLOGY 1982; 70:1367-72. [PMID: 16662681 PMCID: PMC1065889 DOI: 10.1104/pp.70.5.1367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
At least four different proteinases are present in senescing apple leaves (Malus domestica Borkh. cv. Golden Delicious) as determined by their pH optima, substrate specificity, and their reactivity to proteinase inhibitors. An enzyme active at pH 4.5 to 5.0 appears to be a sulfhydryl-dependent (iodoacetamide and phenylmercuric acetate-sensitive) endoproteinase, and degradation of the large subunit of ribulose bisphosphate carboxylase was observed only with this enzyme. It is tentatively concluded that this endoproteinase is responsible for the breakdown of ribulose bisphosphate carboxylase in vivo. However, the presence of more than one endoproteinase in apple leaves is suggested by the broad range of pH optima of the SH-dependent enzyme. Another enzyme active at pH 6.0 appears to be a carboxypeptidase, and was sensitive to phenylmethylsulfonylfluoride. This enzyme showed a strong hydrolytic activity against carbobenzoxyphenylalanylalanine. A sulfhydryl-dependent aminopeptidase and a second hydroxyl-dependent carboxypeptidase were active at pH 7.5Total autolytic activity (the sulfhydryl-dependent endoproteinase) as measured by the disappearance of proteins decreased during the period of protein decline. Evidence is presented that the measured proteinase activity can be dependent on assay methods and substrates. While the disappearance of protein measures most of endo-type activity, the ninhydrin assay appears to measure exo-type activity preferentially.
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117
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Kang SM, Titus JS. Isolation and partial characterization of an Acid endoprotease present in dormant apple shoot bark. PLANT PHYSIOLOGY 1980; 66:984-9. [PMID: 16661565 PMCID: PMC440765 DOI: 10.1104/pp.66.5.984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A major protease present in dormant bark tissues of the apple (Malus domestica Borkh. cv. "Golden Delicious") was partially purified by hemoglobin-coupled Sepharose column chromatography. The protease active at pH 4.6 and at temperatures of 30 to 50 C was found to be sulfhydryl-dependent. Phenylmercuric acetate inhibited the enzyme approximately 50% at 2 millimolar, whereas phenylmethylsulfonyl fluoride inhibited less than 30% even at 10 millimolar. Substrate specificity and the separation of the enzyme reaction products indicated that the enzyme is likely to be an endoprotease. We suggest that the storage proteins in apple bark tissue undergo some modification prior to their eventual hydrolysis to amino acids, which requires a multi-enzyme system(s). Evidence is presented that the apple bark protein extracts enzymically release ninhydrin-positive compounds upon storage at 5 C. It is concluded that the activation of the sulfhydryl-dependent acid endoprotease is associated with the rapid metabolism of storage proteins which accompanies bud break upon regrowth.
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118
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Kapoor A, Kang SM, Trimboli MA. Studies of enzyme active sites. Synthesis and catalytic properties of L-histidylglycyl-L-aspartyl-L-seryl-L-phenylalanine. J Pharm Sci 1970; 59:129-30. [PMID: 5411319 DOI: 10.1002/jps.2600590132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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