scholarly journals A lipid-protein hybrid model for tight junction

2008 ◽  
Vol 295 (6) ◽  
pp. F1601-F1612 ◽  
Author(s):  
David B. N. Lee ◽  
Nora Jamgotchian ◽  
Suni G. Allen ◽  
Michael B. Abeles ◽  
Harry J. Ward
Keyword(s):  
Tight Junction ◽  
Hybrid Model ◽  
Protein Interactions ◽  
Large Body ◽  
Wide Acceptance ◽  
Associated Proteins ◽  
Epithelial Tight Junction ◽  
Lipid Protein Interactions ◽  
And Function ◽  
Adjoining Cell

The epithelial tight junction (TJ) was first described ultrastructurally as a fusion of the outer lipid leaflets of the adjoining cell membrane bilayers (hemifusion). The discovery of an increasing number of integral TJ and TJ-associated proteins has eclipsed the original lipid-based model with the wide acceptance of a protein-centric model for the TJ. In this review, we stress the importance of lipids in TJ structure and function. A lipid-protein hybrid model accommodates a large body of information supporting the lipidic characteristics of the TJ, harmonizes with the accumulating evidence supporting the TJ as an assembly of lipid rafts, and focuses on an important, but relatively unexplored, field of lipid-protein interactions in the morphology, physiology, and pathophysiology of the TJ.

scholarly journals Function of Protein S-Palmitoylation in Immunity and Immune-Related Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuqi Zhang ◽  
Ziran Qin ◽  
Wenhuan Sun ◽  
Feng Chu ◽  
Fangfang Zhou
Keyword(s):  
Protein Interactions ◽  
Protein Function ◽  
Mammalian Cells ◽  
Large Body ◽  
Protein S ◽  
Cellular Membrane ◽  
Immune Signaling ◽  
Substrate Protein ◽  
Associated Proteins ◽  
Immunologic Diseases

Protein S-palmitoylation is a covalent and reversible lipid modification that specifically targets cysteine residues within many eukaryotic proteins. In mammalian cells, the ubiquitous palmitoyltransferases (PATs) and serine hydrolases, including acyl protein thioesterases (APTs), catalyze the addition and removal of palmitate, respectively. The attachment of palmitoyl groups alters the membrane affinity of the substrate protein changing its subcellular localization, stability, and protein-protein interactions. Forty years of research has led to the understanding of the role of protein palmitoylation in significantly regulating protein function in a variety of biological processes. Recent global profiling of immune cells has identified a large body of S-palmitoylated immunity-associated proteins. Localization of many immune molecules to the cellular membrane is required for the proper activation of innate and adaptive immune signaling. Emerging evidence has unveiled the crucial roles that palmitoylation plays to immune function, especially in partitioning immune signaling proteins to the membrane as well as to lipid rafts. More importantly, aberrant PAT activity and fluctuations in palmitoylation levels are strongly correlated with human immunologic diseases, such as sensory incompetence or over-response to pathogens. Therefore, targeting palmitoylation is a novel therapeutic approach for treating human immunologic diseases. In this review, we discuss the role that palmitoylation plays in both immunity and immunologic diseases as well as the significant potential of targeting palmitoylation in disease treatment.

Lipid–Protein Interactions in Plasma Membrane Organization and Function

2022 ◽  
Vol 51 (1) ◽  
Author(s):  
Taras Sych ◽  
Kandice R. Levental ◽  
Erdinc Sezgin
Keyword(s):  
Plasma Membrane ◽  
Protein Interactions ◽  
Collective Behavior ◽  
Protein Function ◽  
Lipid Binding ◽  
Publication Date ◽  
Membrane Organization ◽  
Lipid Protein Interactions ◽  
And Function ◽  
Specific Lipid

Lipid–protein interactions in cells are involved in various biological processes, including metabolism, trafficking, signaling, host–pathogen interactions, and transmembrane transport. At the plasma membrane, lipid–protein interactions play major roles in membrane organization and function. Several membrane proteins have motifs for specific lipid binding, which modulate protein conformation and consequent function. In addition to such specific lipid–protein interactions, protein function can be regulated by the dynamic, collective behavior of lipids in membranes. Emerging analytical, biochemical, and computational technologies allow us to study the influence of specific lipid–protein interactions, as well as the collective behavior of membranes on protein function. In this article, we review the recent literature on lipid–protein interactions with a specific focus on the current state-of-the-art technologies that enable novel insights into these interactions. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Microtubules are required for efficient epithelial tight junction homeostasis and restoration

2014 ◽  
Vol 307 (3) ◽  
pp. C245-C254 ◽  
Author(s):  
Lila G. Glotfelty ◽  
Anita Zahs ◽  
Catalin Iancu ◽  
Le Shen ◽  
Gail A. Hecht
Keyword(s):  
Tight Junction ◽  
Vital Role ◽  
Structure And Function ◽  
Paracellular Transport ◽  
Microtubule Disruption ◽  
Junction Protein ◽  
Epithelial Tight Junction ◽  
And Function ◽  
Junction Structure

Epithelial tight junctions are critical for creating a barrier yet allowing paracellular transport. Although it is well established that the actin cytoskeleton is critical for preserving the dynamic organization of the tight junction and maintaining normal tight junction protein recycling, contributions of microtubules to tight junction organization and function remain undefined. The aim of this study is to determine the role of microtubules in tight junction homeostasis and restoration. Our data demonstrate that occludin traffics on microtubules and that microtubule disruption perturbs tight junction structure and function. Microtubules are also shown to be required for restoring barrier function following Ca2+ chelation and repletion. These processes are mediated by proteins participating in microtubule minus-end-directed trafficking but not plus-end-directed trafficking. These studies show that microtubules participate in the preservation of epithelial tight junction structure and function and play a vital role in tight junction restoration, thus expanding our understanding of the regulation of tight junction physiology.

First Encounter: How Pathogens Compromise Epithelial Transport

Physiology ◽  
2004 ◽  
Vol 19 (5) ◽  
pp. 240-244 ◽  
Author(s):  
Karl Kunzelmann ◽  
Brendan McMorran
Keyword(s):  
Ion Channels ◽  
Tight Junction ◽  
Signaling Pathways ◽  
Epithelial Transport ◽  
Structure And Function ◽  
Electrolyte Transport ◽  
Physiological Functions ◽  
Epithelial Tight Junction ◽  
And Function ◽  
Do So

Pathogenic organisms trigger numerous signaling pathways that ultimately lead to drastic changes in physiological functions. Apart from altering structure and function of the epithelial tight junction barrier and activating inflammatory cascades, they induce changes in fluid and electrolyte transport. Pathogens do so by activating or by inhibiting ion channels and transporters, and the result might be to their benefit or to their disadvantage.

Characterization of microtubules by dark-field STEM and replication

1991 ◽  
Vol 49 ◽  
pp. 152-153
Author(s):  
S.B. Andrews ◽  
R.D. Leapman ◽  
P.E. Gallant ◽  
T.S. Reese
Keyword(s):  
Protein Interactions ◽  
Low Dose ◽  
Unit Length ◽  
Dark Field ◽  
Carbon Films ◽  
Microtubule Associated Proteins ◽  
Molecular Weights ◽  
Freeze Dried ◽  
Protein Motors ◽  
Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

Sign in / Sign up

Export Citation Format

Share Document