極性タンパク質Par-3は,p75NTRと直接相互作用して,ミエリン形成を調節する
Jonah R Chan1, Christine Jolicoeur, Junji Yamauchi
1Department of Cell and Neurobiology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles 90089, USA. jonah.chan@usc.edu
まとめ
細胞極性タンパク質Par-3は,シュヴァン細胞のミエリン化に不可欠である. Par-3を乱したり,p75ニューロトロフィン受容体との相互作用を妨害すると,この重要なプロセスが損なわれます.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- 発達生物学 発達生物学とは
背景:
- 細胞の極性は,移動や分裂のような細胞機能にとって根本的なものです.
- シュヴァン細胞のミエリン化は,偏ったプロセスですが,その背後にあるメカニズムは完全に理解されていません.
研究 の 目的:
- シュヴァンン細胞ミエリン化における細胞極性の役割を調査する.
- ミエリン化に関与する特定の極性タンパク質とメカニズムを特定する.
主な方法:
- シュヴァン細胞のPar-3局所化を評価した.
- 過剰表現とノックダウンによるPar-3レベルの操作.
- Par-3とp75ニューロトロフィン受容体の相互作用を調べました.
主要な成果:
- Par-3は,シュヴァン細胞の軸索-膠質交差点で非対称的に局所することが判明しました.
- Par-3局所化の障害は,骨髄形成を著しく抑制しました.
- Par-3はp75ニューロトロフィン受容体と直接結合し,p75ニューロトロフィン受容体を軸索-膠質交差点に誘導し,重要な複合体を形成することが示された.
結論:
- Par-3は,ミエリン化に必要な細胞の極性を確立する上で重要な役割を果たします.
- Par-3/p75ニューロトロフィン受容体複合体は,シュワン細胞によるミエリン化が成功するために不可欠です.
関連する概念動画
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Regulation of Nuclear Protein Sorting
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Tail-anchoring of Proteins in the ER Membrane
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
Protein Modifications in the RER
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Catenins
Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...


