scholarly journals High dose of baicalin or baicalein can reduce tight junction integrity by partly targeting the first PDZ domain of zonula occludens-1 (ZO-1)

2020 ◽  
Vol 887 ◽  
pp. 173436 ◽  
Author(s):  
Misaki Hisada ◽  
Minami Hiranuma ◽  
Mio Nakashima ◽  
Natsuko Goda ◽  
Takeshi Tenno ◽  
...  
Keyword(s):  
Tight Junction ◽  
Pdz Domain ◽  
High Dose ◽  
Zonula Occludens ◽  
Zonula Occludens 1

scholarly journals Spatial Overlap of Claudin- and Phosphatidylinositol Phosphate-Binding Sites on the First PDZ Domain of Zonula Occludens 1 Studied by NMR

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2465 ◽  
Author(s):  
Hidekazu Hiroaki ◽  
Kaori Satomura ◽  
Natsuko Goda ◽  
Yukako Nakakura ◽  
Minami Hiranuma ◽  
...  
Keyword(s):  
Tight Junction ◽  
Binding Site ◽  
Solution Structure ◽  
Pdz Domain ◽  
Molecular Surface ◽  
Head Group ◽  
Functional Domain ◽  
Phosphate Binding ◽  
Zonula Occludens ◽  
Zonula Occludens 1

Background: The tight junction is an intercellular adhesion complex composed of claudins (CLDs), occludin, and the scaffolding proteins zonula occludens 1 (ZO-1) and its two paralogs ZO-2 and ZO-3. ZO-1 is a multifunctional protein that contains three PSD95/Discs large/ZO-1(PDZ) domains. A key functional domain of ZO-1 is the first PDZ domain (ZO-1(PDZ1)) that recognizes the conserved C-termini of CLDs. Methods: In this study, we confirmed that phosphoinositides bound directly to ZO-1(PDZ1) by biochemical and solution NMR experiments. We further determined the solution structure of mouse ZO-1(PDZ1) by NMR and mapped the phosphoinositide binding site onto its molecular surface. Results: The phosphoinositide binding site was spatially overlapped with the CLD-binding site of ZO-1(PDZ1). Accordingly, inositol-hexaphosphate (phytic acid), an analog of the phosphoinositide head group, competed with ZO-1(PDZ)-CLD interaction. Conclusions: The results suggested that the PDZ domain–phosphoinositide interaction plays a regulatory role in biogenesis and homeostasis of the tight junction.

scholarly journals Decreased ZO1 expression causes loss of time-dependent tight junction function in the liver of ob/ob mice

2021 ◽  
Author(s):  
Yuya Tsurudome ◽  
Nao Morita ◽  
Michiko Horiguchi ◽  
Kentaro Ushijima
Keyword(s):  
Tight Junction ◽  
Dark Period ◽  
Vital Role ◽  
Time Dependent ◽  
Signal Transduction System ◽  
Binding Ability ◽  
Protein Levels ◽  
Multiple Organs ◽  
Zonula Occludens ◽  
Zonula Occludens 1

Abstract Diabetes patients are at a high risk of developing complications related to angiopathy and disruption of the signal transduction system. The liver is one of the multiple organs damaged during diabetes. Few studies have evaluated the morphological effects of adhesion factors in diabetic liver. The influence of diurnal variation has been observed in the expression and functioning of adhesion molecules to maintain tissue homeostasis associated with nutrient uptake. The present study demonstrated that the rhythm-influenced functioning of tight junction was impaired in the liver of ob/ob mice. The tight junctions of hepatocytes were loosened during the dark period in normal mice compared to those in ob/ob mice, where the hepatocyte gaps remained open throughout the day. The time-dependent expression of zonula occludens 1 (ZO1) in the liver plays a vital role in the functioning of the tight junction. The time-dependent expression of ZO1 was nullified and its expression was attenuated in the liver of ob/ob mice. ZO1 expression was inhibited at the mRNA and protein levels. The expression rhythm of ZO1 was found to be regulated by heat shock factor (HSF)1/2, the expression of which was reduced in the liver of ob/ob mice. The DNA-binding ability of HSF1/2 was decreased in the liver of ob/ob mice compared to that in normal mice. These findings suggest the involvement of impaired expression and functioning of adhesion factors in diabetic liver complications.

scholarly journals Identification of PDZ Domain Containing Proteins Interacting with 1.2 and PMCA4b

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Doreen Korb ◽  
Priscilla Y. Tng ◽  
Vladimir M. Milenkovic ◽  
Nadine Reichhart ◽  
Olaf Strauss ◽  
...  
Keyword(s):  
Pdz Domain ◽  
Pdz Domains ◽  
Hek 293 ◽  
Zonula Occludens ◽  
C Terminus ◽  
293 Cells ◽  
Interaction Partners ◽  
Voltage Dependent ◽  
Interaction Domains ◽  
Zonula Occludens 1

PDZ (PSD-95/Disc large/Zonula occludens-1) protein interaction domains bind to cytoplasmic protein C-termini of transmembrane proteins. In order to identify new interaction partners of the voltage-gated L-type Ca2+ channel 1.2 and the plasma membrane Ca2+ ATPase 4b (PMCA4b), we used PDZ domain arrays probing for 124 PDZ domains. We confirmed this by GST pull-downs and immunoprecipitations. In PDZ arrays, strongest interactions with 1.2 and PMCA4b were found for the PDZ domains of SAP-102, MAST-205, MAGI-1, MAGI-2, MAGI-3, and ZO-1. We observed binding of the 1.2 C-terminus to PDZ domains of NHERF1/2, Mint-2, and CASK. PMCA4b was observed to interact with Mint-2 and its known interactions with Chapsyn-110 and CASK were confirmed. Furthermore, we validated interaction of 1.2 and PMCA4b with NHERF1/2, CASK, MAST-205 and MAGI-3 via immunoprecipitation. We also verified the interaction of 1.2 and nNOS and hypothesized that nNOS overexpression might reduce Ca2+ influx through 1.2. To address this, we measured Ca2+ currents in HEK 293 cells co-expressing 1.2 and nNOS and observed reduced voltage-dependent 1.2 activation. Taken together, we conclude that 1.2 and PMCA4b bind promiscuously to various PDZ domains, and that our data provides the basis for further investigation of the physiological consequences of these interactions.

scholarly journals Ankrd1-mediated signaling is supported by its interaction with zonula occludens-1

2014 ◽  
Vol 66 (3) ◽  
pp. 1233-1242 ◽  
Author(s):  
Aleksandra Nestorovic ◽  
Jovana Jasnic-Savovic ◽  
Georgine Faulkner ◽  
Dragica Radojkovic ◽  
Snezana Kojic
Keyword(s):  
Intracellular Signaling ◽  
Pdz Domain ◽  
Mechanical Stretch ◽  
Regulatory Function ◽  
Skeletal Muscle Differentiation ◽  
Multiprotein Complex ◽  
Zonula Occludens ◽  
Binding Partners ◽  
Zonula Occludens 1

The muscle ankyrin repeat protein Ankrd1 is localized in a mechanosensory complex of the sarcomeric I-band. It is involved in signaling pathways activated in response to mechanical stretch. It also acts as a transcriptional cofactor in the nucleus, playing an important role in cardiogenesis and skeletal muscle differentiation. To investigate its regulatory function in signaling we employed protein array methodology and identified 10 novel Ankrd1 binding partners among PDZ domain proteins known to act as platforms for multiprotein complex assembly. The zonula occludens protein-1 (ZO-1) was chosen for further analysis since its interaction with Ankrd2 had already been demonstrated. Both Ankrd2 and Ankrd1 have similar functions and localize in the same regions. We confirmed the interaction of Ankrd1 with ZO-1 protein and determined their subcellular distribution in HeLa cells, showing their colocalization in the cytoplasm. Our findings corroborate the role of Ankrd1 in intracellular signaling.

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