Qhov sib txawv tseem ceeb ntawm adherens junctions thiab desmosomes yog tias adherens junctions tsis muaj cov qauv txiav txim siab hauv lawv cheeb tsam extracellular, thaum desmosomes muaj cov qauv txiav txim siab hauv lawv cheeb tsam extracellular.
Intercellular adhesive junctions yog cov qauv nplaum sib txawv uas muab cov nplaum nplaum, cohesion, thiab kev sib txuas ntawm tes ntawm cov hlwb. Cov kev sib txuas no feem ntau muaj nyob hauv cov hlwb epithelial. Cov qauv no qhia muaj zog txuas rau ib leeg thiab rau cov matrix extracellular. Adherens junctions thiab desmosomes yog ob qho tseem ceeb intercellular nplaum qauv tam sim no nyob rau hauv lub cev.
Adherens Junctions yog dab tsi?
Adherens junctions (AJs) yog cell-to-cell adhesion complexes uas txuas ntxiv sib sau ua ke thiab dissemble, tso cai rau cov hlwb los teb rau biochemical signals, rog, thiab kev hloov pauv hauv cov ntaub so ntswg. AJ yog qhov sib txuas ntawm tes, thiab nws lub ntsej muag cytoplasmic txuas rau actin cytoskeletons. Lawv feem ntau tshwm sim raws li ib ncig ntawm lub xov tooj ntawm tes los yog me ntsis txuas mus rau lub extracellular matrix.
Daim duab 01: Adherens Junction
AJs yog tsim los ntawm plaub cov proteins. Lawv yog cadherins, delta catenin, plakoglobin, thiab alpha-catenin. Cadherins yog transmembrane proteins uas tsim homodimers nyob rau hauv ib tug calcium-dependent yam. Delta catenin, uas tseem hu ua p120, khi juxta membrane thaj tsam ntawm cadherin. Plakoglobin lossis gamma-catenin khi catenin khi thaj chaw hauv cadherin. Alpha catenin khi cadherin los ntawm beta-catenin lossis plakoglobin ncaj qha los txuas cov actin cytoskeleton nrog cadherin. Kev tsim ntawm AJs mus los ntawm kev pib, cadherin recruitment, thiab recruitment ntawm cov quav hniav proteins. Cov haujlwm ntawm AJs yog pib thiab ruaj khov ntawm cell-to-cell adhesions, intracellular signaling, kev tswj ntawm actin cytoskeleton, thiab kev tswj hwm kev hloov pauv.
Dab tsi yog Desmosomes?
Desmosomes yog cov qauv ntawm tes uas tshwj xeeb hauv cell-to-cell adhesions. Lawv yog cov khoom siv sib txuas feem ntau koom nrog hauv cell cohesion. Nws yog ib hom cell junction complex uas localizes qhov chaw zoo li adhesions ntawm ob sab ntawm plasma membranes. Desmosomes yog ib qho ntawm cov muaj zog tshaj ntawm adhesion. Lawv tshwj xeeb tshaj yog pom nyob rau hauv cov ntaub so ntswg thiab muaj kev ntxhov siab txhua yam xws li cov nqaij pob txha, plab hnyuv mucosa, epithelia, thiab zais zis cov ntaub so ntswg.
Daim duab 2: Desmosomes
Desmosomes yog tsim los ntawm desmosome-intermediate filament complexes (DIFC), suav nrog cadherin proteins, linker proteins, thiab keratin intermediate filaments. DIFCs muaj peb cheeb tsam: cheeb tsam extracellular core los yog desmoglea, txheej tuab plaque (ODP), thiab inner ntom plaque (IDP). Hauv desmosomes, muaj ob qhov sib txawv ntawm cov plaque proteins. Lawv yog plakoglobins thiab plakophilins, uas yog nyob rau hauv armadillo rov qab protein tsev neeg, thiab plakin tsev neeg, uas muaj xws li desmoplakin, envoplakin, periplakin, thiab plectin. Thaum lub sijhawm txav ntawm keratinocytes los ntawm cov txheej txheem epidermal, lawv tsim thiab khaws cov desmosomes ntawm lub cell periphery.
Dab tsi zoo sib xws ntawm AdherensJunctions thiab Desmosomes?
- Adherens junctions thiab desmosomes yog intercellular junctions.
- Lawv pab kom adhesion thiab cohesion.
- Ob leeg muaj cov cell adhesion molecules.
- Ntxiv mus, lawv yog qhov tseem ceeb rau kev txhim kho thiab kev ncaj ncees ntawm cov ntaub so ntswg vertebrate.
- Ob leeg muaj ntau hom cadherin ua cell adhesion molecules.
- Ob leeg adherens junctions thiab desmosomes yog anchoring junctions.
Qhov txawv ntawm Adherens Junctions thiab Desmosomes yog dab tsi?
Adherens junctions tsis muaj cov qauv txiav txim siab hauv lawv cheeb tsam extracellular, thaum desmosomes muaj cov qauv txiav txim siab hauv lawv cheeb tsam extracellular. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm adherens junctions thiab desmosomes. Adherens junctions yeej ib txwm muaj calcium-nyob, thaum desmosomes yog calcium-yooj yim hyper-adhesions. Ntxiv mus, adherens junctions tsis muaj plaque proteins, tab sis desmosomes muaj cov plaque protein sib txawv.
Cov hauv qab no qhia txog qhov sib txawv ntawm adherens junctions thiab desmosomes hauv daim ntawv tabular rau kev sib piv ntawm ib sab.
Summary – Adherens Junctions vs Desmosomes
Intercellular adhesive junctions yog cov qauv nplaum sib txawv uas muab cov nplaum nplaum, cohesion, thiab kev sib txuas ntawm tes ntawm cov hlwb. Adherens junctions thiab desmosomes yog ob qho tseem ceeb intercellular nplaum qauv tam sim no nyob rau hauv lub cev. Adherens junctions tsis muaj cov qauv txiav txim siab hauv lawv cheeb tsam extracellular, thaum desmosomes muaj cov qauv txiav txim siab hauv lawv cheeb tsam extracellular. Adherens junctions tswj cov txheej txheem ntawm tes sib txawv xws li cov duab ntawm tes, kev faib, kev loj hlob, apoptosis, thiab kev ua haujlwm tsis zoo, tab sis desmosomes tsis koom nrog ntau lub zog ntawm tes uas tsis yog kev sib koom tes ntawm tes. Ntxiv mus, adherens junctions yeej ib txwm calcium-dependant, tab sis desmosomes yog calcium-yooj yim hyper-adhesions. Yog li, qhov no qhia txog qhov sib txawv ntawm adherens junctions thiab desmosomes.
