B細胞抗原受容体とタンパク質チロシンキナーゼの関連付け Lyn Lyn
Y Yamanashi1, T Kakiuchi, J Mizuguchi
1Department of Oncology, University of Tokyo, Japan.
まとめ
抗原がB細胞と結合すると,信号が発信されます. Lynタンパク質チロシンキナーゼはB細胞表面IgMと結合し,抗原媒介細胞の成長と分化におけるその役割を示唆しています.
科学分野:
- 免疫学 免疫学とは
- 細胞シグナル伝達 細胞信号伝達
- バイオケミストリー バイオケミストリー
背景:
- B細胞の活性化には,抗原と交叉結合する膜結合免疫グロブリン (Igs) が含まれる.
- タンパク質チロシンキナーゼは,B細胞の増殖と分化シグナル伝達に不可欠です.
- SrcのようなチロシンキナーゼLynは,主にB細胞で発現する.
研究 の 目的:
- リンと膜に結合したIgMとの関連性を調査する.
- B細胞における抗原媒介信号伝導におけるLynの役割を決定する.
主な方法:
- リンタンパク質とそのキナーゼ活性と,洗剤細胞溶解物からのIgMとの共免疫プレシピテーション.
- 膜に結合したIgMクロスリンクの後のB細胞におけるチロシンリン酸化パターンの分析.
主要な成果:
- リンタンパク質とそのキナーゼ活性が,IgMと共免疫的に発生した.
- 膜に結合したIgMのクロスリンクは,複数のB細胞タンパク質のチロシンリン酸化を急速に増加させた.
- Lynは,膜に結合したIgMと物理的に関連しています.
結論:
- Lynは,膜に結合したIgMと物理的に関連しています.
- リンキナーゼは,B細胞への抗原結合によって開始される信号伝導経路に関与しています.
- この関連は,リンが抗原媒介のB細胞の増殖と分化に関与していることを示唆している.
関連する概念動画
Enzyme-linked Receptors
Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Receptor Tyrosine Kinases
Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:
Diversity of Antigen Receptors
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
B Cell Activation and Differentiation
The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...


