scholarly journals Assembly of multiple dystrobrevin-containing complexes in the kidney

2000 ◽  
Vol 113 (15) ◽  
pp. 2715-2724
Author(s):  
N.Y. Loh ◽  
S.E. Newey ◽  
K.E. Davies ◽  
D.J. Blake
Keyword(s):  
Skeletal Muscle ◽  
Protein Complexes ◽  
Cell Types ◽  
Epithelial Morphogenesis ◽  
Basal Region ◽  
Molecular Architecture ◽  
Renal Epithelial Cells ◽  
Specific Antibodies ◽  
Different Cell Types ◽  
Deficient Mice

Dystrophin is the key component in the assembly and maintenance of the dystrophin-associated protein complex (DPC) in skeletal muscle. In kidney, dystroglycan, an integral component of the DPC, is involved in kidney epithelial morphogenesis, suggesting that the DPC is important in linking the extracellular matrix to the internal cytoskeleton of kidney epithelia. Here, we have investigated the molecular architecture of dystrophin-like protein complexes in kidneys from normal and dystrophin-deficient mice. Using isoform-specific antibodies, we show that the different cell types that make up the kidney maintain different dystrophin-like complexes. These complexes can be broadly grouped according to their dystrobrevin content: beta-dystrobrevin containing complexes are present at the basal region of renal epithelial cells, whilst alpha-dystrobrevin-1 containing complexes are found in endothelial and smooth muscle cells. Furthermore, these complexes are maintained even in the absence of all dystrophin isoforms. Thus our data suggest that the functions and assembly of the dystrophin-like complexes in kidney differ from those in skeletal muscle and implicate a protein other than dystrophin as the primary molecule in the assembly and maintenance of kidney complexes. Our findings also provide a possible explanation for the lack of kidney pathology in Duchenne muscular dystrophy patients and mice lacking all dystrophin isoforms.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

scholarly journals Subcellular Localization of a Novel Alternative Splicing of IIIG9 and Colocalization with PPP1gamma Isoforms

2008 ◽  
Vol 14 (S3) ◽  
pp. 141-143
Author(s):  
C. Sousa ◽  
A.P. Vintém ◽  
M. Fardilha ◽  
O. da Cruz e Silva ◽  
E. da Cruz e Silva
Keyword(s):  
Alternative Splicing ◽  
Male Infertility ◽  
Cell Types ◽  
Sperm Cells ◽  
Regulatory Subunits ◽  
Specific Antibodies ◽  
Fluorescent Microscope ◽  
Bovine Sperm ◽  
Spermatogonia Cells ◽  
Different Cell Types

In testis we find mainly PPP1gamma2 isoform. We hypothesize that in different cell types we can find different regulatory subunits that may constitute targets for therapeutics of diseases such as male infertility, cancer and Alzheimer's disease. We identified a novel alternative splicing isoform of IIIG9 in testis, a known regulator of PPP1, IIIG9sT, and the aim of this study was its further characterization. We used a specific antibody for IIIG9sT in order to characterize its localization in bovine sperm cells. We also transfected IIIG9sT-GFP construct in mouse spermatogonia cells (GC-1 cells) and we used specific antibodies for each PPP1 isoform for the colocalization studies. We observed them under a fluorescent microscope and a LSM and quantified a high co-localization with PPP1gamma1 and 2 isoforms.

scholarly journals Chromogranin A in the Human Gastrointestinal Tract: An Immunocytochemical Study with Region-specific Antibodies

2002 ◽  
Vol 50 (11) ◽  
pp. 1487-1492 ◽  
Author(s):  
Guida Maria Portela-Gomes ◽  
Mats Stridsberg
Keyword(s):  
Chromogranin A ◽  
Cell Types ◽  
The Other ◽  
Gi Tract ◽  
Human Gastrointestinal Tract ◽  
Double Immunofluorescence ◽  
Gastrin Cells ◽  
Specific Antibodies ◽  
Ec Cells ◽  
Different Cell Types

We studied the immunoreactivity of 12 different region-specific antibodies to the chromogranin A (CgA) molecule in the various neuroendocrine cell types of the human gastrointestinal (GI) tract by using double immunofluorescence techniques. These staining results were compared with others obtained with a commercial monoclonal CgA antibody (LK2H10). G (gastrin)-cells showed immunoreactivity to virtually all region-specific antibodies, but with varying frequency. Most intestinal EC (enterochromaffin)- and L (enteroglucagon)-cells were immunoreactive to the antibodies to the N-terminal and mid-portion of the CgA molecule, whereas the EC-cells in the stomach reacted with fewer region-specific antibodies. D (somatostatin)-cells reacted to the CgA 411–424 antibody and only occasionally showed immunoreactivity to the other CgA antibodies. A larger cytoplasmic area was stained with the antibodies to CgA 17–38 and 176–195 than with the other antibodies tested. These differences in staining pattern may reflect different cleavage of the CgA molecule in different cell types and at different regions of the GI tract.

scholarly journals A PDZ-containing Scaffold Related to the Dystrophin Complex at the Basolateral Membrane of Epithelial Cells

1999 ◽  
Vol 145 (2) ◽  
pp. 391-402 ◽  
Author(s):  
Amy M. Kachinsky ◽  
Stanley C. Froehner ◽  
Sharon L. Milgram
Keyword(s):  
Skeletal Muscle ◽  
Fluorescent Protein ◽  
Protein Complexes ◽  
Basolateral Membrane ◽  
Pdz Domain ◽  
Cell Types ◽  
Protein Domain ◽  
Ph Domain ◽  
Green Fluorescent ◽  
Dystrophin Complex

Membrane scaffolding complexes are key features of many cell types, serving as specialized links between the extracellular matrix and the actin cytoskeleton. An important scaffold in skeletal muscle is the dystrophin-associated protein complex. One of the proteins bound directly to dystrophin is syntrophin, a modular protein comprised entirely of interaction motifs, including PDZ (protein domain named for PSD-95, discs large, ZO-1) and pleckstrin homology (PH) domains. In skeletal muscle, the syntrophin PDZ domain recruits sodium channels and signaling molecules, such as neuronal nitric oxide synthase, to the dystrophin complex. In epithelia, we identified a variation of the dystrophin complex, in which syntrophin, and the dystrophin homologues, utrophin and dystrobrevin, are restricted to the basolateral membrane. We used exogenously expressed green fluorescent protein (GFP)-tagged fusion proteins to determine which domains of syntrophin are responsible for its polarized localization. GFP-tagged full-length syntrophin targeted to the basolateral membrane, but individual domains remained in the cytoplasm. In contrast, the second PH domain tandemly linked to a highly conserved, COOH-terminal region was sufficient for basolateral membrane targeting and association with utrophin. The results suggest an interaction between syntrophin and utrophin that leaves the PDZ domain of syntrophin available to recruit additional proteins to the epithelial basolateral membrane. The assembly of multiprotein signaling complexes at sites of membrane specialization may be a widespread function of dystrophin-related protein complexes.

scholarly journals Current Strategies for the Regeneration of Skeletal Muscle Tissue

2021 ◽  
Vol 22 (11) ◽  
pp. 5929
Author(s):  
Emine Alarcin ◽  
Ayca Bal-Öztürk ◽  
Hüseyin Avci ◽  
Hamed Ghorbanpoor ◽  
Fatma Dogan Guzel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Tissue ◽  
Muscle Regeneration ◽  
Striated Muscle ◽  
Cell Types ◽  
Skeletal Muscle Tissue ◽  
Skeletal Muscle Regeneration ◽  
Muscle Repair ◽  
Clinical Implementation ◽  
Different Cell Types

Traumatic injuries, tumor resections, and degenerative diseases can damage skeletal muscle and lead to functional impairment and severe disability. Skeletal muscle regeneration is a complex process that depends on various cell types, signaling molecules, architectural cues, and physicochemical properties to be successful. To promote muscle repair and regeneration, various strategies for skeletal muscle tissue engineering have been developed in the last decades. However, there is still a high demand for the development of new methods and materials that promote skeletal muscle repair and functional regeneration to bring approaches closer to therapies in the clinic that structurally and functionally repair muscle. The combination of stem cells, biomaterials, and biomolecules is used to induce skeletal muscle regeneration. In this review, we provide an overview of different cell types used to treat skeletal muscle injury, highlight current strategies in biomaterial-based approaches, the importance of topography for the successful creation of functional striated muscle fibers, and discuss novel methods for muscle regeneration and challenges for their future clinical implementation.

scholarly journals Benzimidazole derivative small-molecule 991 enhances AMPK activity and glucose uptake induced by AICAR or contraction in skeletal muscle

2016 ◽  
Vol 311 (4) ◽  
pp. E706-E719 ◽  
Author(s):  
Laurent Bultot ◽  
Thomas E. Jensen ◽  
Yu-Chiang Lai ◽  
Agnete L. B. Madsen ◽  
Caterina Collodet ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transport ◽  
Energy Homeostasis ◽  
Ex Vivo ◽  
Benzimidazole Derivative ◽  
Cell Types ◽  
Α Subunit ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase ◽  
Different Cell Types

AMP-activated protein kinase (AMPK) plays diverse roles and coordinates complex metabolic pathways for maintenance of energy homeostasis. This could be explained by the fact that AMPK exists as multiple heterotrimer complexes comprising a catalytic α-subunit (α1 and α2) and regulatory β (β1 and β2)- and γ (γ1, γ2, γ3)-subunits, which are uniquely distributed across different cell types. There has been keen interest in developing specific and isoform-selective AMPK-activating drugs for therapeutic use and also as research tools. Moreover, establishing ways of enhancing cellular AMPK activity would be beneficial for both purposes. Here, we investigated if a recently described potent AMPK activator called 991, in combination with the commonly used activator 5-aminoimidazole-4-carboxamide riboside or contraction, further enhances AMPK activity and glucose transport in mouse skeletal muscle ex vivo. Given that the γ3-subunit is exclusively expressed in skeletal muscle and has been implicated in contraction-induced glucose transport, we measured the activity of AMPKγ3 as well as ubiquitously expressed γ1-containing complexes. We initially validated the specificity of the antibodies for the assessment of isoform-specific AMPK activity using AMPK-deficient mouse models. We observed that a low dose of 991 (5 μM) stimulated a modest or negligible activity of both γ1- and γ3-containing AMPK complexes. Strikingly, dual treatment with 991 and 5-aminoimidazole-4-carboxamide riboside or 991 and contraction profoundly enhanced AMPKγ1/γ3 complex activation and glucose transport compared with any of the single treatments. The study demonstrates the utility of a dual activator approach to achieve a greater activation of AMPK and downstream physiological responses in various cell types, including skeletal muscle.

Metabolic fingerprinting of cell types in mouse skeletal muscle by combining TOF-SIMS with immunofluorescence staining

The Analyst ◽  
2020 ◽  
Vol 145 (21) ◽  
pp. 6901-6909 ◽  
Author(s):  
Zhe Song ◽  
Zhaoying Wang ◽  
Hansen Zhao ◽  
Lesi Cai ◽  
Zhanping Li ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Tissue ◽  
Cell Types ◽  
Skeletal Muscle Tissue ◽  
Immunofluorescence Staining ◽  
Immunofluorescent Staining ◽  
Fiber Types ◽  
Mouse Skeletal Muscle ◽  
Tof Sims ◽  
Different Cell Types

Skeletal muscle tissue is composed of various fiber types which differ in metabolic capacities. TOF-SIMS was combined with immunofluorescent staining to investigate metabolic fingerprints among different cell types in mouse skeletal muscle tissue.

scholarly journals Signalling Properties of Inositol Polyphosphates

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5281
Author(s):  
Tania Maffucci ◽  
Marco Falasca
Keyword(s):  
Enzymatic Activity ◽  
Protein Complexes ◽  
Cell Types ◽  
Pharmacological Interventions ◽  
Inositol Polyphosphates ◽  
Cellular Processes ◽  
New Information ◽  
Different Cell Types

Several studies have identified specific signalling functions for inositol polyphosphates (IPs) in different cell types and have led to the accumulation of new information regarding their cellular roles as well as new insights into their cellular production. These studies have revealed that interaction of IPs with several proteins is critical for stabilization of protein complexes and for modulation of enzymatic activity. This has not only revealed their importance in regulation of several cellular processes but it has also highlighted the possibility of new pharmacological interventions in multiple diseases, including cancer. In this review, we describe some of the intracellular roles of IPs and we discuss the pharmacological opportunities that modulation of IPs levels can provide.

The alpha 6 beta 1 (VLA-6) and alpha 6 beta 4 protein complexes: tissue distribution and biochemical properties

1990 ◽  
Vol 96 (2) ◽  
pp. 207-217 ◽  
Author(s):  
A. Sonnenberg ◽  
C.J. Linders ◽  
J.H. Daams ◽  
S.J. Kennel
Keyword(s):  
Monoclonal Antibodies ◽  
Protein Complexes ◽  
Cell Types ◽  
Biochemical Properties ◽  
Immunoperoxidase Staining ◽  
Tissue Sections ◽  
Adult Mice ◽  
Carcinoma Cell Lines ◽  
Different Cell Types ◽  
Human And Mouse

A member of the integrin family, the alpha 6 beta 4 complex was previously identified on human and mouse carcinoma cell lines by using a rat monoclonal antibody to alpha 6. Here we describe two monoclonal antibodies that recognize epitopes on the beta 4 subunit of the human and mouse alpha 6 beta 4 complexes. The monoclonal antibodies against beta 4 were able to preclear alpha 6 beta 4, but not alpha 6 beta 1 from cell line extracts. A substantial fraction of the total beta 4 subunits present on the cell surface was not associated with alpha 6, as it could not be removed by anti-alpha 6 antibodies, but remained precipitable with anti-beta 4 antibodies. There was no evidence for novel alpha subunits associated with beta 4. The alpha 6 subunit consists of disulfide-linked heavy and light chains. The variability in size of these two chains from different cell types is largely due to differences in modifications of N-linked glycans. Additional heterogeneity may be caused by differential proteolytic cleavage of the alpha 6 precursor. Immunoperoxidase staining of tissue sections of neonatal and adult mice revealed that beta 4 expression is limited to epithelial tissues and peripheral nerves. The alpha 6 subunit has a wider distribution that includes all tissues and cells stained by antibodies against beta 4. Cells and tissue that are positive for alpha 6, but negative for beta 4, may express the alpha 6 beta 1 complex.

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