膀輸送受容体のシンタキシンファミリー
M K Bennett1, J E García-Arrarás, L A Elferink
1Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University Medical Center, California 94305.
Cell
|September 10, 1993
まとめ
シンタキシンは,神経系におけるシナプス膀のドッキングに不可欠なタンパク質です. この研究は,シンタキシンの一族を特定し,細胞内輸送と膜標的化におけるそれらの役割を明らかにした.
科学分野:
- 分子および細胞生物学
- 神経科学は神経科学である.
背景:
- シンタキシンAとBは,シナプス胞のドッキングに関与する神経系特異のタンパク質です.
- ネズミで6つの関連性のあるシンタキシンタンパク質のファミリーが特定されています.
研究 の 目的:
- シンタキシンタンパク質ファミリーとその細胞下部局所を特徴づけるため.
- カルシウム調節分泌におけるシンタキシン1Aの役割を調査する.
主な方法:
- シンタキシン間のアミノ酸同一性を決定するための配列分析.
- COS細胞での発現は,サブセルラーターゲティングを研究するために.
- 神経内分泌PC12細胞へのマイクロ注射.
主要な成果:
- シンタキシンは23%から84%のアミノ酸同一性を共有し,膜アンカリングのためのカルボキシ-ターミナル水害ドメインを有しています.
- シンタキシンは広範な組織分布を示し,異なる細胞下部を標的とする.
- シンタキシン1Aは,PC12細胞のカルシウム調節分泌に不可欠である.
結論:
- シンタキシンは,細胞内輸送小胞の受容体の一族を構成する.
- 特定のシンタキシンメンバーは,膀の密輸のための明確な標的膜を識別する可能性が高い.
関連する概念動画
Overview of Secretory Vesicles
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Fusion of Secretory Vesicles with the Plasma Membrane
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
SNAREs and Membrane Fusion
Once a transport vesicle has recognized its target organelle, the vesicular membrane needs to fuse with the target membrane to unload the cargo. Transmembrane proteins called SNAREs present on organelle membranes and their vesicles, mediate vesicle fusion.
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
Vesicular Tubular Clusters
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...
Clathrin Coated Vesicles
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.


