File:Dystrophin within the plasma membrane of muscle fibres.jpg

This image is a visual display of the muscle fibre membrane and the location of dystrophin within the sarcolemma surrounding each muscle fibre.

There are 4 main transmembrane proteins that compose the dystrophin-glycoprotein complex (DGP), also referred to as the dystrophin-associated protein complex (DAPC), located in the muscle fibre membrane.

These proteins include:

• Sarcoglycans: a family of transmembrane proteins that work in conjunction with other proteins (namely dystrophin) to protect muscle fibres during contraction. There are 4 main types present in striated muscle, including: α-sarcoglycan, β-sarcoglycan, γ-sarcoglycan and δ-sarcoglycan. The sarcoglycan complex is disrupted and destabilized from the plasma membrane when dystrophin is mutated and hence leads to eccentric contraction-induced disruption of the plasma membrane of smooth and cardiac muscle. [1]

• Dystroglycan: connects the extracellular matrix and cytoskeleton and also forms a linkage between the dystrophin-glycoprotein complex and the basal lamina. When dystrophin is mutated, these linkages formed by dystroglycan are lost and also cause the disruption of the plasma membrane.[2]

• Syntrophin: links to the extracellular matrix through dystrophin and creates signal transduction complexes at the DAPC and therefore when dystrophin is mutated, this crucial signalling pathway is lost. [3]

• Dystrobrevinis: the functional role of this complex has not yet been clearly identified, however studies show that dystrobrevin disappears from the muscle membrane in Duchenne muscular dystrophy (DMD). [4]

C terminus or terminal refers to the end of an amino acid chain. This end is terminated by a carboxyl group. N terminus or terminal refers to the beginning of an amino acid chain. This starts the chain with an amine group.

Image creator: Ashleigh Pontifex (z3332629) Student image constructed based on the image presented on: http://www.mda.org/publications/fa-dmdbmd-what.html

Additional information obtained from: http://www.mda.org/publications/Quest/q134resup.html

Location of dystrophin within the muscle fibre membrane by Ashleigh Pontifex is licensed under a Creative Commons Attribution-NoDerivs 3.0 Unported License. Based on a work at www.mda.org.

<a rel="license" href="http://creativecommons.org/licenses/by-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nd/3.0/88x31.png" /></a> Location of dystrophin within the muscle fibre membrane by Ashleigh Pontifex is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nd/3.0/">Creative Commons Attribution-NoDerivs 3.0 Unported License</a>. Based on a work at <a xmlns:dct="http://purl.org/dc/terms/" href="http://www.mda.org/publications/fa-dmdbmd-what.html" rel="dct:source">www.mda.org</a>.

Assessment

+ This is a very relevant drawing for the group topic. You have included a full description of what is shown. - The description looks like you have simply coy and pasted directly from another source, there is no [1] - [4] identified. You should have attempted to explain your own figure if there were references these should have been included here.

Note - This image was originally uploaded as part of a student project and may contain inaccuracies in either description or acknowledgements. Students have been advised in writing concerning the reuse of content and may accidentally have misunderstood the original terms of use. If image reuse on this non-commercial educational site infringes your existing copyright, please contact the site editor for immediate removal.

Cite this page: Hill, M.A. (2024, April 23) Embryology Dystrophin within the plasma membrane of muscle fibres.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Dystrophin_within_the_plasma_membrane_of_muscle_fibres.jpg

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G.