Regulation of SIGNALLING PATHWAYS INVOLVING NUCLEAR FACTOR KAPPA B

涉及核因子 KAPPA B 的信号通路的调控

• 批准号: 7732474
• 负责人: michael j lenardo
• 金额: $ 75.66万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7732474
• 关键词: Adjustment Disorders; Affinity; Antigen Receptors; B-Lymphocytes; Binding; Biochemical; Biochemical Genetics; Biology; Cells; Circadian Rhythm Pathway; Clinical; Communicable Diseases; Complex; Condition; Cytoplasm; DNA Sequence; DNA-Binding Proteins; Degenerative Disorder; Development; Gene Activation; Gene Expression Regulation; Gene Family; Genes; Genetic Transcription; HIV; IGK@ gene cluster; IL2 gene; Immune; Immune Response Genes; Immune System Diseases; Immune response; Immunoglobulins; Immunologic Deficiency Syndromes; Infectious Agent; Inflammatory; Interleukin-2; KH Domain; Lead; Life Cycle Stages; Link; Lymphocyte; Malignant Neoplasms; Mass Spectrum Analysis; Membrane Proteins; NF-kappa B; Nucleic Acids; Numbers; Output; Pathway interactions; Pharmacologic Substance; Phosphorylation; Phosphotransferases; Physiological; Play; Protein Binding; Protein Family; Protein Kinase; Proteins; Receptors, Antigen, B-Cell; Regulation; Regulator Genes; Ribosomal Proteins; Role; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Site; Stimulus; Surface; T-Cell Receptor; T-Lymphocyte; TNFRSF5 gene; Ubiquitination; gene induction; genetic regulatory protein; human disease; immune function; inhibitor/antagonist; novel; p65; pathogen; programs; protein activation; prototype; response; therapeutic target; v-rel Oncogenes

Regulation of many immune response genes depend on a 10 bp DNA sequence termed kappaB. This sequence is bound by a family of protein factors related to the Rel oncogene. The prototype transcription complex binding to the sequence, termed NF-kappaB, has been conventionally defined as a heterodimer between a P50 DNA binding protein and a P65 (RelA) activation protein that is typically sequestered in the cytoplasm by a protein called I-kappaB. Following certain types of stimulation to the cell, a specific protein kinase complex called I-kappaB kinase causes the phosphorylation of I-kappaB followed by its ubiquitination and degradation. Among the stimuli that can release NF-kappaB is the triggering of the T cell receptor (TCR) or B cell receptor (BCR) by antigen during an immune response. While studying a rare clinical condition of immunodeficiency, we discovered that NF-kappaB has a more complex subunit composition than previously suspected. Specifically, we found that genes such as IL-2 and I-kB harbor kappaB sites of a particular sequence that bind a trimeric complex containing p50, p65, and ribosomal protein small subunit 3 (RPS3). RPS3 is a K-homology domain-containing protein that binds single-stranded nucleic acids and dramatically enhances the affinity of the p50 and p65 Rel-homology proteins to these select kappaB sites. A subset of all NF-kappaB genes are dependent on RPS3 including crucial physiological functions such as expression of the immunoglobulin kappa light chain gene in B cells and the interleukin-2 gene in T cells. This establishes a new paradigm for NF-kappaB gene regulation that potentially explains the selective activation of genes by distinct inducers of NF-kappaB. Given the pivotal role of NF-kappaB and Indians cell gene regulation, we are looking for other subunits that may also participate in the binding complex. We are also attempting to identify inhibitors of this component, since inhibition of NF-kappaB is a prime therapeutic target for number of inflammatory and degenerative conditions. Inhibition of NF-kappaB may also be useful for various infectious diseases involving pathogens, such as HIV, that utilize this factor for their life cycle or pathogenic effects. We have also been studying the activation circuitry that induces NF-kappaB after triggering the antigen receptor on B cells or T cells. We have found a new kinase that plays a direct role in physically linking the membrane-associated protein complex containing the Carma 1, MALT 1, and the Bcl-10 (CBM) proteins to the I-kappaB kinase complex. We have demonstrated a vital role for the cellular kinase in the induction pathway. This novel kinase has both a positive and negative regulatory role is transducing the signals from antigen receptors at the surface of lymphocytes to the gene induction apparatus. This kinase has been shown to beinvolved in developmental and circadian rhythm pathways and now appears to play a key role in immune function. We will be studying the biochemical features of its regulation to understand how it might be modulated in various diseases of the immune system. Mass spectrometry analysis has also revealed other proteins in the signal transduction pathway involving the CBM complex and experimentation will be directed to elucidating the functional role of these proteins.

许多免疫应答基因的调节依赖于称为kappaB的10 bp DNA序列。该序列被与Rel癌基因相关的蛋白质因子家族结合。 与该序列结合的原型转录复合物，称为NF-κ B，通常被定义为P50 DNA结合蛋白和P65（RelA）活化蛋白之间的异二聚体，其通常被称为I-kappaB的蛋白质隔离在细胞质中。在对细胞进行某些类型的刺激后，一种称为I-kappaB激酶的特异性蛋白激酶复合物引起I-kappaB的磷酸化，随后是其泛素化和降解。在能够释放NF-κ B的刺激物中，有一种是在免疫应答过程中抗原对T细胞受体（TCR）或B细胞受体（BCR）的触发。 在研究一种罕见的免疫缺陷临床状况时，我们发现NF-κ B具有比以前怀疑的更复杂的亚基组成。 具体地说，我们发现IL-2和I-kB等基因具有特定序列的kappaB位点，该位点结合含有p50、p65和核糖体蛋白小亚基3（RPS3）的三聚体复合物。 RPS3是一种含有K-同源结构域的蛋白，其结合单链核酸并显著增强p50和p65 Rel-同源蛋白对这些选择的kappaB位点的亲和力。 所有NF-κ B基因的一个子集依赖于RPS 3，包括关键的生理功能，如免疫球蛋白κ轻链基因在B细胞中的表达和白细胞介素-2基因在T细胞中的表达。 这为NF-κ B基因调控建立了一个新的范例，可能解释了NF-κ B不同诱导剂对基因的选择性激活。鉴于NF-κ B和印第安人细胞基因调控的关键作用，我们正在寻找其他亚基，也可能参与结合复合物。我们还试图确定该组分的抑制剂，因为抑制NF-κ B是许多炎症和退行性疾病的主要治疗靶点。 NF-κ B的抑制也可用于涉及病原体的各种感染性疾病，例如HIV，其利用该因子用于其生命周期或致病作用。 我们也一直在研究触发B细胞或T细胞上的抗原受体后诱导NF-κ B的激活电路。 我们已经发现了一种新的激酶，它在将包含Carma 1、MALT 1和Bcl-10（CBM）蛋白的膜相关蛋白复合物与I-kappaB激酶复合物物理连接中起直接作用。 我们已经证明了细胞激酶在诱导途径中的重要作用。 这种新的激酶具有正性和负性调节作用，将信号从淋巴细胞表面的抗原受体传递到基因诱导装置。 这种激酶已被证明参与发育和昼夜节律途径，现在似乎在免疫功能中发挥关键作用。 我们将研究其调节的生化特征，以了解它如何在各种免疫系统疾病中被调节。 质谱分析还揭示了涉及煤层气复合物的信号传导途径中的其他蛋白质，实验将致力于阐明这些蛋白质的功能作用。