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61.
62.
Kinesin-1 drives the movement of diverse cargoes, and it has been proposed that specific kinesin light chain (KLC) isoforms target kinesin-1 to these different structures. Here, we test this hypothesis using two in vitro motility assays, which reconstitute the movement of rough endoplasmic reticulum (RER) and vesicles present in a Golgi membrane fraction. We generated GST-tagged fusion proteins of KLC1B and KLC1D that included the tetratricopeptide repeat domain and the variable C-terminus. We find that preincubation of RER with KLC1B inhibits RER motility, whereas KLC1D does not. In contrast, Golgi fraction vesicle movement is inhibited by KLC1D but not KLC1B reagents. Both RER and vesicle movement is inhibited by preincubation with the GST-tagged C-terminal domain of ubiquitous kinesin heavy chain (uKHC), which binds to the N-terminal domain of uKHC and alters its interaction with microtubules. We propose that although the TRR domains are required for cargo binding, it is the variable C-terminal region of KLCs that are vital for targeting kinesin-1 to different cellular structures. 相似文献
63.
Minqi Hu Wei Liu Pingchuan Ma Yingyi Wu Honglin Li Yi Men Xiufa Tang Lin Que Yubin Cao Chunjie Li 《Experimental biology and medicine (Maywood, N.J.)》2021,246(11):1269
Submandibular glands have essential functions in taste, mastication, swallowing, and digestion. Submandibular gland hypofunction is prevalent in the elderly, impairing the patients’ quality of life. Current clinical treatment strategies have not decelerated or reversed the pathological process of submandibular gland hypofunction. Therefore, novel restoration strategies should be explored. However, studies on the mechanism of aging-related submandibular gland hypofunction remain very limited. The role of the TGF-β/Smad pathway in fibrosis has been studied in other organs. Therefore, this study aimed to elucidate the role of TGF-β/Smad signaling in the aging-related submandibular gland hypofunction. The results showed that Smad7 knockout in mice decreased the salivary flow rate. H&E, Masson trichrome, and immunohistochemistry staining of MCP-1 and α-SMA showed that Smad7 knockout in mice resulted in lymphocytic infiltration, acinar cell atrophy, and interstitial fibrosis. The Western blotting of collagen I and III also confirmed extensive fibrosis. We then found that Smad7 depletion resulted in the TGF-β-mediated fibrosis via mir-21, mir-29, and np_5318, and NFκB-driven inflammation activation. This study confirmed the inhibitory role of Smad7 in the aging-related submandibular gland hypofunction. Therefore, it provided a promising treatment target for aging-related dysfunction and sialadenitis of submandibular gland. 相似文献
64.
Plants have developed a range of strategies for resisting environmental stresses. One of the most common is the synthesis
and deposition of callose, which functions as a barrier against stress factor penetration. The aim of our study was to examine
whether callose forms an efficient barrier against Pb penetration in the roots of Lemna minor L. exposed to this metal. The obtained results showed that Pb induced callose synthesis in L. minor roots, but it was not deposited regularly in all tissues and cells. Callose occurred mainly in the protoderm and in the centre
of the root tip (procambial central cylinder). Moreover, continuous callose bands, which could form an efficient barrier for
Pb penetration, were formed only in the newly formed and anticlinal cell walls (CWs); while in other CWs, callose formed only
small clusters or incomplete bands. Such an arrangement of callose within root CWs inefficiently protected the protoplast
from Pb penetration. As a result, Pb was commonly present inside the root cells. In the light of the results, the barrier
role of callose against metal ion penetration appears to be less obvious than previously believed. It was indicated that induction
of callose synthesis is not enough for a successful blockade of the stress factor penetration. Furthermore, it would appear
that the pattern of callose distribution has an important role in this defence strategy. 相似文献
65.
Bing Pan Yijing Ma Hui Ren Yubin He Yongyu Wang Xiaofeng Lv Donghui Liu Liang Ji Baoqi Yu Yuhui Wang Y. Eugene Chen Subramaniam Pennathur Jonathan D. Smith George Liu Lemin Zheng 《PloS one》2012,7(11)
Background
Diabetic HDL had diminished capacity to stimulate endothelial cell (EC) proliferation, migration, and adhesion to extracellular matrix. The mechanism of such dysfunction is poorly understood and we therefore sought to determine the mechanistic features of diabetic HDL dysfunction.Methodology/Principal Findings
We found that the dysfunction of diabetic HDL on human umbilical vein endothelial cells (HUVECs) was associated with the down regulation of the HDL receptor protein, SR-BI. Akt-phosphorylation in HUVECs was induced in a biphasic manner by normal HDL. While diabetic HDL induced Akt phosphorylation normally after 20 minutes, the phosphorylation observed 24 hours after diabetic HDL treatment was reduced. To determine the role of SR-BI down regulation on diminished EC responses of diabetic HDL, Mouse aortic endothelial cells (MAECs) were isolated from wild type and SR-BI (−/−) mice, and treated with normal and diabetic HDL. The proliferative and migratory effects of normal HDL on wild type MAECs were greatly diminished in SR-BI (−/−) cells. In contrast, response to diabetic HDL was impaired in both types suggesting diminished effectiveness of diabetic HDL on EC proliferation and migration might be due to the down regulation of SR-BI. Additionally, SR-BI down regulation diminishes diabetic HDL’s capacity to activate Akt chronically.Conclusions/Significance
Diabetic HDL was dysfunctional in promoting EC proliferation, migration, and adhesion to matrix which was associated with the down-regulation of SR-BI. Additionally, SR-BI down regulation diminishes diabetic HDL’s capacity to activate Akt chronically. 相似文献66.
Lipid transfer inhibitor protein (LTIP) is a physiologic regulator of cholesteryl ester transfer protein (CETP) function. We previously reported that LTIP activity is localized to LDL, consistent with its greater inhibitory activity on this lipoprotein. With a recently described immunoassay for LTIP, we investigated whether LTIP mass is similarly distributed. Plasma fractionated by gel filtration chromatography revealed two LTIP protein peaks, one coeluting with LDL, and another of approximately 470 kDa. The 470 kDa LTIP complex had a density of 1.134 g/ml, indicating approximately 50% lipid content, and contained apolipoprotein A-I. By mass spectrometry, partially purified 470 kDa LTIP also contains apolipoproteins C-II, D, E, J, and paraoxonase 1. Unlike LDL-associated LTIP, the 470 kDa LTIP complex does not inhibit CETP activity. In normolipidemic subjects, approximately 25% of LTIP is in the LDL-associated, active form. In hypercholesterolemia,this increases to 50%, suggesting that lipoprotein composition may influence the status of LTIP activity. Incubation (37 degrees C) of normolipidemic plasma increased active, LDL-associated LTIP up to 3-fold at the expense of the inactive pool. Paraoxon inhibited this shift by 50%. Overall, these studies show that LTIP activity is controlled by its reversible incorporation into an inactive complex. This may provide for short-term fine-tuning of lipoprotein remodeling mediated by CETP. 相似文献
67.
Fuying?Ma Zheng?Xiong Yubin?Zheng Xiaochen?Yu Xiaoyu?ZhangEmail author 《World journal of microbiology & biotechnology》2008,24(11):2627-2632
A repeated batch operation is developed for the treatment of alkaline pulp black liquor, through a process of biological acidification
precipitation of lignin using brown rot fungus Fomitopsis sp. IMER2. The results showed that COD and color removal of black liquor was dependent on the biomass concentration, pH decrease
and initial COD. Based on these results, the repeated batch process was successfully carried out 12 times over 36 days in
an air bubble column bioreactor. The average reduction of COD and color was approximately 40% and 70%, respectively. 相似文献
68.
Molecular mechanisms underlying SHP-1 gene expression. 总被引:2,自引:0,他引:2
69.
70.