scholarly journals Association of myosin with the connecting cilium of rod photoreceptors

1992 ◽  
Vol 103 (1) ◽  
pp. 183-190 ◽  
Author(s):  
D.S. Williams ◽  
M.A. Hallett ◽  
K. Arikawa
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Actin Filaments ◽  
Critical Role ◽  
Rod Outer Segments ◽  
Outer Segments ◽  
Vertebrate Photoreceptor ◽  
Sds Page ◽  
Membrane Morphogenesis ◽  
Muscle Myosin

The cilium of a vertebrate photoreceptor cell connects the phototransductive outer segment of the cell to the inner segment. Previous studies have shown that, within the connecting cilium, there is a small cluster of actin filaments, which play a critical role in the formation of new disk membranes. Here, we have detected a polypeptide in rat rod outer segments that is recognized by myosin heavy chain antibodies and was found to possess other characteristics of conventional non-muscle myosin heavy chain: it comigrates in SDS-PAGE with non-muscle myosin heavy chain; it associates with the cytoskeleton of rod outer segments in an ATP-sensitive manner; and it binds to purified actin filaments in the absence of ATP. Myosin ATPase activity was also detected in isolated rod outer segments. Electron immunomicroscopy revealed that myosin is present in the small actin-containing domain within the connecting cilium at the site of disk membrane morphogenesis. These results pose the possibility that an actin-myosin contractile mechanism functions in the formation of new photoreceptor disk membranes.

scholarly journals Comparison of New ELISA Method With Established SDS-PAGE Method for Determination of Muscle Myosin Heavy Chain Isoforms

2011 ◽  
pp. 899-904 ◽  
Author(s):  
J. ŘÍČNÝ ◽  
T. SOUKUP
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myosin Heavy Chain Isoforms ◽  
Elisa Method ◽  
Comparative Measurement ◽  
Sds Page ◽  
Myhc Isoforms ◽  
Methodological Approaches ◽  
Muscle Myosin

We developed a new method for the quantitative determination of myosin heavy chain (MyHC) isoforms taking advantage of immunochemical differences and based on the ELISA principle. In the present paper we compare analysis of MyHC isoforms using the SDS-PAGE and the ELISA methods in the same samples of adult female inbred Lewis strain euthyroid, hyperthyroid and hypothyroid rats. In all thyroid states, the same composition and corresponding changes of MyHC isoforms were determined using both methodological approaches in the slow soleus and the fast extensor digitorum longus muscles. Our results showed that ELISA can be used for a “semi-quantitative” or “comparative” measurement of MyHC isoforms in multiple muscle samples, but that it is neither more exact nor faster compared to SDS-PAGE.

scholarly journals Non-muscle myosin heavy chain as a possible target for protein encoded by metastasis-related mts-1 gene.

1994 ◽  
Vol 269 (31) ◽  
pp. 19679-19682 ◽  
Author(s):  
M.V. Kriajevska ◽  
M.N. Cardenas ◽  
M.S. Grigorian ◽  
N.S. Ambartsumian ◽  
G.P. Georgiev ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Muscle Myosin

Expression of Desmin and Smooth Muscle Myosin Heavy Chain in Dermatofibromas

2002 ◽  
Vol 126 (10) ◽  
pp. 1179-1183 ◽  
Author(s):  
Andrea K. Bruecks ◽  
Martin J. Trotter
Keyword(s):  
Smooth Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Smooth Muscle Actin ◽  
Smooth Muscle Myosin ◽  
Immunoperoxidase Staining ◽  
Muscle Actin ◽  
Muscle Myosin ◽  
Hematoxylin Eosin ◽  
Focal Expression

Abstract Background.—The histopathologic features of dermatofibroma vary remarkably, and this diversity may occasionally cause problems in differentiating between benign and malignant mesenchymal lesions, including smooth muscle neoplasms. Immunohistochemical stains are sometimes necessary to clarify the histogenesis of a lesion. Objective.—To evaluate dermatofibromas for expression of desmin and smooth muscle myosin heavy chain (SM-MHC) antigens, which are commonly used as evidence of smooth muscle differentiation. Methods.—We studied 100 consecutive cases of dermatofibroma using hematoxylin-eosin–stained sections and immunoperoxidase staining with antibodies against desmin, SM-MHC, and smooth muscle actin. Results.—We found focal positivity for desmin in 9 cases, and in 2 of these cases, at least 10% of lesional cells showed strong expression. We found focal staining for SM-MHC in 10 cases, and in 2 of these cases, at least 10% of the lesional cells were positive. Regions positive for desmin and/or SM-MHC did not show definite histologic features of myogenous differentiation on hematoxylin-eosin–stained sections. All dermatofibromas expressing desmin and SM-MHC were also strongly positive for smooth muscle actin. Conclusions.—About 10% of dermatofibromas show focal expression of desmin and SM-MHC, and this expression may be present in up to 10% to 15% of lesional cells. Thus, in dermal spindle cell lesions, focal expression of these muscle antigens, like that of smooth muscle actin, is not diagnostic of a smooth muscle tumor.

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