Endocitosi

Abbozzo citologia
Questa voce sull'argomento citologia è solo un abbozzo.
Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Segui i suggerimenti del progetto di riferimento.
Rappresentazione schematica dei diversi tipi di endocitosi.

L'endocitosi è un processo riguardante la periferia cellulare, attraverso il quale la cellula internalizza molecole o corpi presenti nello spazio extracellulare in maniera massiva tramite la modificazione della forma della sua membrana plasmatica, che crea uno spazio per racchiudere il materiale da introdurre nella cellula in una vescicola, detta "vescicola endocitica". Questa vescicola viene quindi convogliata nel citoplasma tramite microtubuli.

L'endocitosi è un processo che richiede consumo di energia da parte della cellula. Tra le sue funzioni vi sono quelle di consentire l'introduzione di strutture cellulari e di molecole ad alto peso molecolare per la loro digestione intracellulare per azione di enzimi idrolitici presenti nei lisosomi, e di consentire l'internalizzazione della membrana cellulare in eccesso e di specifiche molecole esposte sulla sua superficie in modo da regolare la morfologia, l'area e la funzione di segnalazione della membrana plasmatica.

Alcuni processi di endocitosi non portano alla formazione di vescicole destinate a fondersi con lisosomi bensì sono coinvolte nel processo di trasduzione del segnale, ad esempio i caveosomi che si formano per mezzo di proteine specifiche (caveolina).

Si riconoscono tre tipi di endocitosi:

  • Endocitosi mediata da recettori: è regolata e specifica. In questo tipo di endocitosi la cellula riconosce il suo substrato (materiale da ingerire) mediante proteine di membrana. Queste proteine sono in grado di legare, esternamente, il materiale da introdurre e, internamente, particolari proteine chiamate clatrine. Viene così organizzata una rete di clatrine che possiede già una sua curvatura intrinseca e che contribuisce all'invaginazione del plasmalemma. Le clatrine sono organizzate e stabilizzate nella loro struttura reticolare dalle proteine "adattine". Nel momento in cui l'invaginazione deve richiudersi su se stessa interviene una terza proteina, detta dinamina che, di fatto, "scinde" il plasmalemma dalla nuova membrana protoplasmatica della neoformata vescicola. L'endocitosi mediata da recettori è sfruttata anche dai Virus per entrare nelle cellule ospiti.
  • Endocitosi in fase fluida o pinocitosi: è costitutiva e aspecifica, ossia la cellula introduce piccole gocce di matrice extracellulare (ECM) in maniera indifferenziata. Questo è possibile perché il materiale in questione è presente disciolto in soluzione acquosa. Questo particolare tipo di endocitosi è detto pinocitosi. Nell'endocitosi la cellula ingloba le macromolecole o altre particelle, formando con la propria membrana delle vescicole nel citoplasma.
  • Fagocitosi

Mondo vegetale

L'endocitosi di batteri Rhizobium che si osserva nei noduli delle Leguminose è un evento unico nel mondo vegetale.

Le tappe dell'endocitosi prevedono:

  • Scomparsa della parete del filamento di infezione
  • Invaginazione della membrana plasmatica
  • Esclusione del materiale di matrice del filamento di infezione e formazione del simbiosoma.

In seguito nel rizobio avviene una rapida moltiplicazione cellulare, una endoreduplicazione del DNA, una modifica della superficie cellulare, lo sviluppo della competenza per l'azotofissazione e il finale blocco della divisione cellulare.

Voci correlate

Altri progetti

Collegamenti esterni

  Portale Biologia: accedi alle voci di Wikipedia che trattano di biologia

Read other articles:

List of destroyers of the Imperial Russian Navy

This article provides insufficient context for those unfamiliar with the subject. Please help improve the article by providing more context for the reader. (April 2020) (Learn how and when to remove this template message) Российский Императорский флотRossiiskiy Imperatorskiy flotNaval jack (top) and ensign of the Russian NavyActive1696 – February 1917CountryRussian EmpireMilitary unit 1877–1917 The format is: Name, launch year, place of construction (if foreign...

 

João Braz de Aviz

His EminenceJoão Braz de AvizCardinal Prefect of the Congregation for Institutes of Consecrated Life and Societies of Apostolic LifeAppointed4 January 2011PredecessorFranc RodeOther post(s)Cardinal priest of Sant’Elena fuori Porta PrenestinaOrdersOrdination26 November 1972by Romeu AlbertiConsecration31 May 1994by Domingos Gabriel WisniewskiCreated cardinal18 February 2012by Pope Benedict XVIRankCardinal deacon (2012–22)Cardinal priest (2022–present)Personal detailsBornJoão ...

 

Frédéric Gagey

Frédéric GageyGagey during a conference in TehranBorn (1956-06-29) 29 June 1956 (age 67)Vesoul, FranceNationalityFrenchEducationÉcole PolytechniqueENSAE ParisTechOccupationCFO of Air France–KLM Frédéric Gagey (born 29 June 1956) is a French businessman, the current CFO of Air France–KLM.[1][2][3] Gagey is a graduate of the Ecole Polytechnique and the ENSAE School of Economics, Statistics and Finance. He also holds a master's degree in economics from the U...

Benteng Frederik Hendrik

Koordinat: 6°10′14″S 106°49′52″E / 6.170422°S 106.831162°E / -6.170422; 106.831162 Benteng Prins Hendrik di Weltevreden Benteng Prins Frederik, adalah sebuah fortifikasi yang dibangun pada tahun 1837 oleh pemerintah Belanda di Batavia (kini Jakarta), Hindia Belanda (kini Indonesia). Benteng ini terletak di Taman Wilhelmina, yang kemudian dihancurkan sekitar tahun 1961 dan digantikan oleh Masjid Istiqlal. Masyarakat setempat biasa menyebut benteng ini sebaga...

 

العنصرية في الولايات المتحدة

جزء من سلسلة حولالتمييز أشكال عامة عمر طائفة طبقة لون إعاقة نمط وراثي شعر طول لغة مظهر سمات عقلية عرق / أثنية / جنسية رتبة دين جنس توجه جنسي حجم أنواع أشكال محددة   اجتماعية رهاب اللاجنسية وصمة عار الإيدز سلطة البالغين اضطهاد المصابين بالبرص معاداة التشرد معاداة الم...

 

Nonwoven fabric

Sheet of fibers Multiple colored swatches of non-woven fabric Nonwoven fabric or non-woven fabric is a fabric-like material made from staple fibre (short) and long fibres (continuous long), bonded together by chemical, mechanical, heat or solvent treatment. The term is used in the textile manufacturing industry to denote fabrics, such as felt, which are neither woven nor knitted.[1] Some non-woven materials lack sufficient strength unless densified or reinforced by a backing. In recen...

Basse-Saxe

Pour l’article homonyme, voir Cercle de Basse-Saxe. Basse-Saxe Niedersachsen Armoiries Drapeau Localisation de la Basse-Saxe (en vert foncé) à l'intérieur de l'Allemagne. Administration Pays Allemagne Capitale Hanovre Ministre-président Stephan Weil (SPD) ISO 3166-2 DE-NI Démographie Gentilé Bas-Saxon Population 8 027 031 hab. (31/12/2021[1]) Densité 169 hab./km2 Rang 4e PIB (2006)PIB/hab. 197,094 Md € (5e)24 600 € (10e) Géograp...

 

约翰斯顿环礁

此條目可参照英語維基百科相應條目来扩充。 (2021年5月6日)若您熟悉来源语言和主题，请协助参考外语维基百科扩充条目。请勿直接提交机械翻译，也不要翻译不可靠、低品质内容。依版权协议，译文需在编辑摘要注明来源，或于讨论页顶部标记{{Translated page}}标签。 约翰斯顿环礁Kalama Atoll 美國本土外小島嶼 Johnston Atoll 旗幟颂歌：《星條旗》The Star-Spangled Banner約翰斯頓環礁�...

 

OS X Yosemite

OS X v10.10 YosemiteVersi dari sistem operasi OS XDesktop OS X YosemitePembangunApple Inc.Model sumberSumber tertutup (dengan komponen sumber tertutup)Dirilis kemanufaktur16 Oktober 2014Rilis terbaru10.10.3 (Build 14D131)[1] / 8 April 2015; 9 tahun lalu (2015-04-08)Metode updateMac App StorePlatformx86-64Tipe KernelHybrid (sebagian besar Monolitik)LisensiAPSL dan Apple EULADidahului olehOS X v10.9 MavericksSitus resmiSitus web resmiStatus dukunganDukungan utama tanggal 10 Mei 201...

Native American mascot controversy

Controversy regarding the use of Indigenous names and images by sports teams The Atlanta Braves encouraged fans to gesture with the tomahawk chop, distributing foam tomahawks at games and other events.[1] Part of a series onDiscrimination Forms Institutional Structural Statistical Taste-based Attributes Age Caste Class Dialect Disability Genetic Hair texture Height Language Looks Mental disorder Race / Ethnicity Skin color Scientific racism Rank Sex Sexual orientation Species...

 

Space Station 3D

2002 Canadian filmSpace Station 3DDirected byToni MyersWritten byToni MyersProduced byToni MyersNarrated byTom CruiseCinematographyJames NeihouseEdited byToni MyersMusic byMicky ErbeMaribeth SolomonDistributed byIMAX CorporationRelease date April 19, 2002 (2002-04-19) Running time47 minutes[1]CountriesCanadaUnited StatesLanguageEnglishBudget$1 million[2]Box office$127.6 million[3] Space Station 3D (simply known as Space Station in 2D format) is a 2002 C...

 

Joseph Heco

American journalist Joseph Heco Joseph Heco (born Hikozō Hamada (浜田彦蔵, Hamada Hikozō) September 20, 1837 – December 12, 1897) was the first Japanese person to be naturalized as a United States citizen and the first to publish a Japanese language newspaper. Early years Hikozō Hamada was born in Harima province, the son of a local landowner. Following his father's death, his mother remarried. The fatherless boy had been accepted by a temple school for training and education, so...

Mausoleo di Galla Placidia

Mausoleo di Galla PlacidiaEsterno del tempioStato Italia RegioneEmilia-Romagna LocalitàRavenna Indirizzovia San Vitale, 17 e via G. Argentario 22 ‒ Ravenna (RA) Coordinate44°25′16″N 12°11′49″E44°25′16″N, 12°11′49″E ReligioneCristianesimo Arcidiocesi Ravenna-Cervia Stile architettonicopaleocristiano e bizantino Inizio costruzionedopo il 425 Completamentoentro la metà del V secolo Sito webwww.ravennamosaici.it/mausoleo-di-galla-placidia/ Modifica dati su Wikidata...

 

USB hardware

Communication connector using the USB protocol This article is about the physical and electrical aspects of USB connections. For the standard in general, see USB. Various legacy USB connectors along a centimeter ruler for scale. From left to right: Micro-B plugProprietary UC-E6 connector used on many older Japanese cameras for both USB and analog AV outputMini-B plugStandard-A receptacle (non-compliant because USB does not allow extension cables[1])Standard-A plugStandard-B plug The i...

 

هيو دانسي

هيو دانسي (بالإنجليزية: Hugh Dancy)‏  دانسي في مهرجان تورونتو السينمائي الدولي 2011. معلومات شخصية اسم الولادة هيو مايكل هوريس دانسي الميلاد 19 يونيو 1975 (العمر 49 سنة)ستوك أون ترينت، ستافوردشاير ،إنجلترا، المملكة المتحدة الإقامة لندن  مواطنة المملكة المتحدة  الزوجة كلير دي...

لقاح الكوليرا

لقاح الكوليرا   وصف لقاح المرض المستهدف كوليرا نوع قاتل/معطل اعتبارات علاجية معرّفات ك ع ت J07J07AE01 AE01 J07AE02‏ (منظمة الصحة العالمية) J07AE51‏ (منظمة الصحة العالمية) تعديل مصدري - تعديل   لقاح الكوليرا الفموي Euvichol صنع بواسطة شركة EuBiologics الكورية.[1] لقاح الكوليرا هو لقاح...

 

NGC 4475

NGC 4475   جزء من عنقود كوما المجري  الكوكبة الهلبة[1]  رمز الفهرس NGC 4475 (الفهرس العام الجديد)2MASX J12294758+2714362 (Two Micron All-Sky Survey, Extended source catalogue)MCG+05-30-008 (فهرس المجرات الموروفولوجي)PGC 41225 (فهرس المجرات الرئيسية)UGC 7632 (فهرس أوبسالا العام)SDSS J122947.57+271436.0 (مسح سلون الرقمي للسماء)UZC J12294...

 

Bundesstraße 244

Vorlage:Infobox hochrangige Straße/Wartung/DE-B Bundesstraße 244 in Deutschland Karte Verlauf der B 244 Alle Koordinaten: OSM | WikiMap Basisdaten Betreiber: Deutschland Bundesrepublik Deutschland Straßenbeginn: Dedelstorf(52° 42′ 19″ N, 10° 28′ 41″ O52.7052210.47803) Straßenende: Oberharz am Brocken(51° 46′ 12″ N, 10° 48′ 17″ O51.7699510.80471) Gesamtlänge: 157 km Bundesland: Nieders...

Balzan Prize

Award for human endeavor AwardBalzan PrizeBalzan Prize 2017 ceremony in BernAwarded forAchievements in the natural sciences, humanities and cultureCountrySwitzerlandFirst awarded1961Website www.balzan.org/en/balzan-prize www.balzan.org/de www.balzan.org/fr www.balzan.org/it/premio-balzan The International Balzan Prize Foundation awards four annual monetary prizes to people or organizations who have made outstanding achievements in the fields of humanities, natural sciences, culture, as well a...

 

ابن واصل

ابن واصل معلومات شخصية اسم الولادة محمد بن سالم بن نصر الله المازني التميمي الحموي الشافعي الميلاد 20 أبريل 1208   حماة  الوفاة 1 أغسطس 1298 (90 سنة)   حماة  الحياة العملية المهنة مؤرخ،  وسياسي،  وأديب،  ومفكر،  وفيلسوف،  ومُحَدِّث،  وفقيه،  ورياضياتي ...