Qhov sib txawv tseem ceeb ntawm kev sib tshuam nruj thiab kev sib tshuam yog qhov sib txuas nruj yog ib hom kev sib txuas ntawm tes uas koom nrog cov plasma daim nyias nyias ntawm cov hlwb nyob sib ze ua ke, thaum adherens junction yog ib hom kev sib txuas ntawm tes uas koom nrog cov actin filaments ntawm cov hlwb nyob sib ze. ua ke.
Cell junctions yog cov qauv ntawm tes uas muaj ntau yam protein ntau uas muab kev sib cuag ntawm cov hlwb nyob sib ze lossis ib lub xovtooj ntawm tes thiab cov khoom siv ntxiv hauv cov tsiaj. Cov cell junctions muaj ntau pom nyob rau hauv epithelial hlwb. Hauv vertebrates, muaj peb hom kev sib txuas ntawm tes: anchoring junctions (adherens junctions, desmosomes, hemidesmosomes), kis junctions, thiab nruj junctions.
Tight Junction yog dab tsi?
Kev sib txuas nruj yog ib hom kev sib txuas ntawm tes hauv cov pob txha uas koom nrog cov plasma daim nyias nyias ntawm cov hlwb nyob sib ze ua ke. Tight junctions muaj nyob rau hauv cov ntaub so ntswg epithelial ntawm vertebrates. Lawv feem ntau ua raws li cov kev txwv uas tswj kev txav ntawm cov dej thiab solutes ntawm cov txheej txheej epithelial. Nws kuj yog cais raws li ib tug paracellular barrier. Kev txav ntawm cov kua nplaum los ntawm kev sib tshuam nruj heev nyob ntawm qhov loj thiab nqi. Txawm li cas los xij, physiological pH plays lub luag haujlwm tseem ceeb hauv kev xaiv cov kuab tshuaj dhau los ntawm kev sib tshuam nruj. Qhov no yog vim hais tias feem ntau nruj junctions yog me ntsis xaiv rau cations. Yog li ntawd, nruj junctions tam sim no nyob rau hauv ntau hom ntawm epithelia yog xaiv rau kev daws ntawm txawv me me, nqi, thiab polarity.
Daim duab 01: Tight Junction thiab Adherens Junction
Muaj kwv yees li 40 cov proteins koom nrog hauv kev sib tw nruj. Cov proteins no tau muab faib ua plaub yam loj: scaffolding proteins, signaling proteins, regulation proteins, and transmembrane proteins. Lub luag hauj lwm ntawm scaffolding proteins muaj xws li kev npaj cov transmembrane proteins thiab coupling transmembrane proteins mus rau lwm yam cytoplasmic proteins thiab actin filaments. Lub luag haujlwm ntawm cov cim qhia cov protein yog pab hauv kev sib txuas sib txuas, kev tswj hwm kev tswj hwm, thiab kev hloov cov noob. Regulation proteins regulates membrane vesicle targeting. Ntxiv mus, transmembrane proteins muaj xws li junctional adhesion molecules, occludin, thiab claudin. Nws ntseeg tau tias claudin yog cov protein nyob rau hauv qhov sib txuas nruj uas yog lub luag haujlwm rau kev xaiv permeability.
Adherens Junction yog dab tsi?
Adherens junction yog ib hom kev sib txuas ntawm tes uas koom nrog cov actin filaments ntawm cov hlwb nyob sib ze ua ke. Nws tseem yog hu ua zonula adherens, intermediate junction, los yog siv desmosome. Adherens Junction yog ib qho protein complex uas tshwm sim ntawm cell-cell junctions thiab cell-matrix junctions nyob rau hauv epithelial thiab endothelial cov ntaub so ntswg. Lawv ib txwm basal dua li cov junctions nruj.
Daim duab 02: Adherens Junction
Adherens junction yog ib hom kev sib txuas ntawm tes uas nws lub ntsej muag cytoplasmic txuas rau actin cytoskeleton. Nws tshwm sim raws li ib tug band encircling lub cell los yog raws li ib qho chaw ntawm txuas mus rau lub extracellular matrix. Tsis tas li ntawd, adherens junctions yog tsim los ntawm cadherins, p120, γ-catenin, thiab α-catenin.
Dab tsi zoo sib xws ntawm Tight Junction thiab Adherens Junction?
- Tight junctions thiab adherens junctions yog ob hom cell junctions pom nyob rau hauv vertebrates.
- Ob qhov kev sib tshuam yog tsim los ntawm cov protein ntau.
- Lawv muaj nyob hauv cov hlwb epithelial.
- Ob leeg yog cell-cell junctions.
- Lawv tseem ceeb heev hauv kev sib txuas lus ntawm tes.
Qhov txawv ntawm Tight Junction thiab Adherens Junction yog dab tsi?
Ib qho kev sib txuas nruj yog ib hom kev sib txuas ntawm tes sib txuas nrog cov plasma daim nyias nyias ntawm cov hlwb nyob sib ze ua ke, thaum qhov kev sib txuas ua ke yog ib hom kev sib txuas ntawm tes koom nrog cov actin filaments ntawm cov neeg nyob sib ze ua ke. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev sib tshuam nruj thiab adherens junction. Tsis tas li ntawd, ib qho kev sib tshuam nruj muaj cov proteins xws li scaffolding protein, signaling protein, regulation protein, thiab transmembrane protein (adhesion molecule, occludin, and claudin). Ntawm qhov tod tes, qhov sib txuas adherens muaj cov proteins xws li cadherins, p120, γ-catenin, thiab α-catenin.
Cov hauv qab no qhia txog qhov sib txawv ntawm kev sib tshuam nruj thiab kev sib txuas ua ke hauv daim ntawv teev npe rau kev sib piv ntawm ib sab.
Summary – Tight Junction vs Adherens Junction
Cell junctions yog cellular lug nrog ntau yam protein complexes uas muab kev sib cuag ntawm cov hlwb nyob sib ze los yog ib lub xovtooj ntawm tes thiab cov extracellular matrix nyob rau hauv cov tsiaj. Tight junctions thiab adherens junctions yog ob hom cell junctions hauv vertebrates. Ib qho kev sib tshuam nruj koom nrog cov plasma daim nyias nyias ntawm cov hlwb nyob sib ze ua ke, thaum ib qho kev sib txuas ua ke koom nrog cov actin filaments ntawm cov hlwb nyob sib ze ua ke. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev sib tshuam nruj thiab kev sib tshuam adherens.
