The Coat Protein Complex II, or COPII, is a group of proteins that facilitate the formation of vesicles to transport proteins from the endoplasmic reticulum to the Golgi apparatus or endoplasmic-reticulum–Golgi intermediate compartment. This process is termed anterograde transport, in contrast to the retrograde transport associated with the COPI complex. COPII is assembled in two parts: first an inner layer of Sar1, Sec23, and Sec24 forms; then the inner coat is surrounded by an outer lattice of Sec13 and Sec31.
The COPII coat is responsible for the formation of vesicles from the endoplasmic reticulum (ER). These vesicles transport cargo proteins to the Golgi apparatus (in yeast) or the endoplasmic-reticulum-Golgi intermediate compartment (ERGIC, in mammals).[1]
Coat assembly is initiated when the cytosolic Ras GTPase Sar1 is activated by its guanine nucleotide exchange factor Sec12.[1] Activated Sar1-GTP inserts itself into the ER membrane, binding preferentially to areas of membrane curvature. As Sar1-GTP inserts into the membrane, it recruits Sec23 and Sec24 to make up the inner cage.[1] Once the inner coat is assembled, the outer coat proteins Sec13 and Sec31 are recruited to the budding vesicle.[1] Hydrolysis of the Sar1 GTP to GDP promotes disassembly of the coat.
Some proteins are found to be responsible for selectively packaging cargos into COPII vesicles. More recent research suggests the Sec23/Sec24-Sar1 complex participates in cargo selection.[2] For example, Erv29p in Saccharomyces cerevisiae is found to be necessary for packaging glycosylated pro-α-factor.[3]
Sec24 proteins recognize various cargo proteins, packaging them into the budding vesicles.
The COPII coat consists of an inner layer – a flexible meshwork of Sar1, Sec23, and Sec24 – and an outer layer made of Sec13 and Sec31.[1] Sar1 resembles other Ras-family GTPases, with a core of six beta strands flanked by three alpha helices, and two flexible "switch domains". Unlike other Ras GTPases, Sar1 inserts into membranes via an N-terminal helix (rather than myristoylation or prenylation).[1]
These coat proteins are necessary but insufficient to direct or dock the vesicle to the correct target membrane. SNARE, cargo, and other proteins are also needed for these processes to occur.
Pre-budding complex (composed of Sar1-GTP and Sec23/24) recruits the flexible Sec13p/31p complex, characterized by polymerization of the Sec13/31 complex with other Sec13/31 complexes to form a cuboctahedron with a broader lattice than its Clathrin vesicle analog. The formation of the cuboctahedron deforms the ER membrane and detaches the COPII vesicle (alongside cargo proteins and v-SNAREs), completing the COPII vesicle budding process.[2]
The signal(s) that triggers Sec12 to initiate COPII assembly remains unclear, though some regulators of coat formation are now known.[4] The frequency of COPII formation is regulated in part by Sec16A and Tango1 proteins, likely by concentrating Sec12 in a given location, so it can more efficiently activate Sar1.[1]
In mammals there are two Sar1 genes: SAR1A and SAR1B (SAR1B was previously known as SARA2[5]). In cultured mammalian cells the two Sar1 genes appear redundant; however, in animals SAR1B is uniquely required for the formation of large (over 1 micrometer across) COPII-coated vesicles.[1]
Similarly, mammals express two Sec23 genes: SEC23A and SEC23B. The two Sec23 isoforms have identical function but are expressed in different body tissues. Both Sec23 proteins can interact with any of the four Sec24 proteins: SEC24A, SEC24B, SEC24C, and SEC24D.[1]
Lethal or pathogenic variants of most COPII proteins have been described. Loss of Sar1B in mice results in death soon after birth.[6] In humans, inheriting two copies of certain SAR1B variants results in Chylomicron retention disease,[1] and loss of Sar1B causes a combination of chylomicron retention disease and the neuromuscular disorder Marinesco–Sjögren syndrome.[6]
Loss of Sec23A is lethal to mice in utero.[6] In humans, a Sec23A variant causes Cranio-lenticulo-sutural dysplasia, while Sec23B variants are associated with the bone marrow disease congenital dyserythropoietic anemia type II and some cancers.[6][1] Mice without Sec23B die soon after birth.[6] Halperin-Birk syndrome (HLBKS), a rare autosomal recessive neurodevelopmental disorder, is caused by a null mutation in the SEC31A.[7]
CopII has three specific binding sites that can each be complexed. The adjacent picture (Sed5) uses the Sec22 t-SNARE complex to bind. This site is more strongly bound, and therefore is more favored. (Embo)
Mutations the threonine at position 39 to asparagine generates a dominant negative Sar1A bound permanently to GDP; mutating histidine 79 to glycine generates a constitutively active Sar1A, with GTP hydrolysis slowed dramatically.[1]
此条目的主題是1982年電視劇《蘇乞兒》。关于其他“蘇乞兒”相關頁面,請見「蘇乞兒」。 蘇乞兒The Legend of Master So类型清裝武打编剧張毅成、盧新燕、鄧惠玲、馮錦江编导陳宇超、蕭鍵鏗、劉天富、劉仕裕助理编导溫偉基、康命鎏、彭偉明、楊紹鴻、徐念華、譚朗昌主演周潤發、劉德華、苗僑偉、米 雪集数20主题曲忘盡心中情作曲顧嘉煇(兼編曲)作词黃 霑演
Dr. (H.C.) H.Taufiq KiemasS.H., M.H.Ketua Majelis Permusyawaratan Rakyat Republik Indonesia ke-13Masa jabatan1 Oktober 2009 – 8 Juni 2013WakilHajriyanto Y. Thohari Lukman Hakim Saifuddin Melani Leimena Suharli Ahmad Farhan HamidPendahuluHidayat Nur WahidPenggantiSidarto DanusubrotoAnggota Dewan Perwakilan RakyatRepublik IndonesiaMasa jabatan1 Oktober 1999 – 8 Juni 2013PenggantiLowongDaerah pemilihanSumatera Selatan(1999—2004)Jawa Barat II(2004—13)Masa jabatan1 Oktob…
Mubarak Al-Sabah Jeque Mubarak bin Sabah Al-Sabah (1837 - 28 de noviembre, 1915) (árabe: الشيخ مبارك بن صباح الصباح) El Grande fue gobernante (Hakim) de Kuwait desde el 18 de mayo de 1896 hasta su muerte el 28 de noviembre de 1915. Mubarak subió al trono tras la muerte, por asesinato, de su hermano Muhammad bin Sabah. Mubarak es el séptimo gobernante de la dinastía Al-Sabah. Mubarak, además, es padre de dos importantes gobernantes kuwaitíes que los sucedieron , Jaber …
هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (أبريل 2019) روبن جاست معلومات شخصية الميلاد 13 نوفمبر 1987 (36 سنة) براتيسلافا مواطنة ألمانيا الحياة العملية المهنة لاعب هوكي الجليد اللغات الألمانية الرياضة…
علم المخطوطاتجزء من علوم التاريخ المساعدة — bibliology (en) يمتهنه codicologist (en) تعديل - تعديل مصدري - تعديل ويكي بيانات علم الكتب المخطوطة أو كوديكولوجيا (بالإنجليزية: Codicology) هو دراسة الكتب المخطوطة، والكراريس (المجلدات المخاطة، أو «الكودكسات» -جمع كودكس Codex) كأشياء مادية، وخاصة الم
Genus of single-celled organisms General Morphology of Proteromonas spp. By Dasha Klyuchareva Proteromonas Scientific classification (unranked): SAR Superphylum: Heterokonta Phylum: Placidozoa Class: Opalinea Order: Slopalinida Family: Proteromonadidae Genus: ProteromonasKunstler 1883 Synonyms Prowazekella Aléxéieff 1912 Proteromonas (Proteromonas Künstler 1883, Prowazekella) is a genus of single-celled biflagellated microbial eukaryotes belonging to the Superphylum Stramenopiles which are ch…
American online dictionary and encyclopedia that gathers information from a variety of sources The free dictionary redirects here. For the Wikimedia project using the slogan The free dictionary, see Wiktionary. The Free DictionaryScreenshot Type of siteOnline dictionary, encyclopediaAvailable inEnglish, Spanish, German, French, Italian, Chinese, Portuguese, Dutch, Norwegian, Greek, Arabic, Polish, Turkish, Russian[1]OwnerFarlex, Inc.[2]URLwww.thefreedictionary.comRegistratio…
The Production of Security Oorspronkelijke titel De la Production de la Sécurité Auteur(s) Gustave de Molinari Vertaler J. Huston McCulloch[1] Land België, Verenigde Staten Taal Frans (oorspr.), Engels Onderwerp Libertarisme, economie Genre Non-fictie Uitgever The Ludwig von Mises Institute Uitgegeven 2009 Medium Print Pagina's 64 Portaal Literatuur Politieke ideologieën Dit artikel is een deel van de reeks over politiek Ideologie Anarchisme Christendemocratie Communisme…
Canadian soccer player Lars Hirschfeld Hirschfeld with Rosenborg in 2007Personal informationFull name Lars Justin Hirschfeld[1]Date of birth (1978-10-17) 17 October 1978 (age 45)Place of birth Edmonton, Alberta, CanadaHeight 1.90 m (6 ft 3 in)[2]Position(s) GoalkeeperTeam informationCurrent team FC Edmonton (goalkeeping coach)Youth career1997 Edmonton Ital-CanadiansSenior career*Years Team Apps (Gls)1997–1998 Edmonton Drillers (indoor) 1 (0)1998–2000 Energ…
Topik artikel ini mungkin tidak memenuhi kriteria kelayakan umum. Harap penuhi kelayakan artikel dengan: menyertakan sumber-sumber tepercaya yang independen terhadap subjek dan sebaiknya hindari sumber-sumber trivial. Jika tidak dipenuhi, artikel ini harus digabungkan, dialihkan ke cakupan yang lebih luas, atau dihapus oleh Pengurus.Cari sumber: Hatoli – berita · surat kabar · buku · cendekiawan · JSTOR (Pelajari cara dan kapan saatnya untuk menghapus pes…
هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (مارس 2023) يُستخدم مصطلح حسد الفيزياء كمفهومٍ عامٍّ يُوجَّه على شكلِ انتقادٍ للمتخصّصين فيما يُسمَّى «الكتابة الحديثة» وكذلك للأكاديميين العاملين في مجالات مثل الفنون
هذه المقالة بحاجة لصندوق معلومات. فضلًا ساعد في تحسين هذه المقالة بإضافة صندوق معلومات مخصص إليها. بُني قبر سالم تشيشتي في فتحبور سيكري بالهند عام 1581 في عهد الإمبراطور المغولي جلال الدين أكبر. الدرقاعة (بالفارسية: درگاه). هي ضريح مبني على قبر شخصية دينية مقدسة، غالبًا قديس صو
This is the talk page for discussing improvements to the World War II template. Put new text under old text. Click here to start a new topic. New to Wikipedia? Welcome! Learn to edit; get help. Assume good faith Be polite and avoid personal attacks Be welcoming to newcomers Seek dispute resolution if needed Archives: 1 Military history Template‑classThis template is within the scope of the Military history WikiProject. If you would like to participate, please visit the project page, where you …
Laurence Fishburne (2017) Laurence John Fishburne III[1] (* 30. Juli 1961 in Augusta, Georgia) ist ein US-amerikanischer Schauspieler. Inhaltsverzeichnis 1 Leben 2 Filmografie (Auswahl) 3 Videospiele 4 Weblinks 5 Einzelnachweise Leben Schon mit zehn Jahren stand Laurence Fishburne auf einer Bühne in New York City. Mit zwölf gab er sein Debüt vor der Kamera mit der Darstellung des Joshua Hall in der TV-Seifenoper One Life to Live 1973. Sein Kinodebüt gab er 1975 in dem Film Cornbread,…
Historic house in Michigan, United States United States historic placeMinoru and Teruko (Hirashiki) Yamasaki HouseU.S. National Register of Historic Places Interactive mapLocation3717 Lakecrest Dr., Bloomfield Hills, MichiganCoordinates42°35′14″N 83°13′33″W / 42.58722°N 83.22583°W / 42.58722; -83.22583 (Minoru and Teruko (Hirashiki) Yamasaki House)Area0 acres (0 ha)Built1972 (1972)ArchitectMinoru YamasakiNRHP reference No.13000905…
Film genre Horror Movie redirects here. For the Skyhooks song, see Horror Movie (song). This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article may contain excessive or irrelevant examples. Please help improve the article by adding descriptive text and removing less pertinent examples. (January 2017) This article needs additional citations for verification. Please help improve this arti…
Plano de Roma mostrando o Velabro entre o Capitolino e o Palatino Velabro (em latim: Velabrum), e depois Velo Áureo (em latim: Velum Aureum) na Idade Média, é um vale baixo da cidade de Roma situado entre o Monte Capitolino e a encosta noroeste do Palatino. A etimologia de seu nome é desconhecida. Varrão sugeriu que derivou de a vehendo (flutuador), enquanto Plutarco das vela (velas ou cortinas) utilizadas nas procissões. Independente de sua origem, é provavelmente antiga, e originalmente…
Опис файлу Опис Завідувачі кафедр географічного факультету Київського національного університету імені Тараса Шевченка з деканом та його заступниками, 2019 р. Зліва направо: 1-й ряд - О.О. Любіцева, В.К. Хільчевський, Я.Б. Олійник (декан), Л.М. Даценко; 2-й ряд - В.Ф. Пасько (заст. де…
Japanese video game producer Hiroyuki Kimura木村 浩之Born (1965-06-01) June 1, 1965 (age 58)Ishikawa Prefecture, JapanOccupation(s)Video game director, producer and artistEmployerNintendo (1988–present)Notable workSuper MarioMetroidPikminTitleManager at Nintendo EAD (2003–2015)Manager at Nintendo EPD Production Group No. 10 (2015–present) Hiroyuki Kimura (木村 浩之, Kimura Hiroyuki, born June 1, 1965) is a Japanese video game director and producer who works for Nintendo.[1…
Eddie Murray, the all-time leader in games played as a first baseman Games played (most often abbreviated as G or GP) is a statistic used in team sports to indicate the total number of games in which a player has participated (in any capacity); the statistic is generally applied irrespective of whatever portion of the game is contested. In baseball, the statistic applies also to players who, before a game, are included on a starting lineup card or are announced as ex ante substitutes, whether or…
Lokasi Pengunjung: 18.188.126.29