1 / 10

Dystrophin and the Extracellular Matrix

Dystrophin and the Extracellular Matrix. Eric Niederhoffer SIU-SOM. Protein domain structure Dystrophin glycoprotein complex Contraction unit Cytoskeletal linkages at sarcolemma Muscle proteins and disease Creatine kinase and CKI In situ staining and Western blots.

llincoln
Download Presentation

Dystrophin and the Extracellular Matrix

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dystrophin and the Extracellular Matrix Eric Niederhoffer SIU-SOM • Protein domain structure • Dystrophin glycoprotein complex • Contraction unit • Cytoskeletal linkages at sarcolemma • Muscle proteins and disease • Creatine kinase and CKI • In situ staining and Western blots

  2. Dystrophin Domain Structure Domains of the dystrophin molecule. The N terminus contains the primary actin-binding site, whereas the C terminus contains the -dystroglycan, dystrobrevin, and syntrophin-binding sites. The N- and C-terminal domains are connected by 24 spectrin-like repeats, some of which have been shown to bind actin. The four "hinge" regions are denoted H1-H4. http://www.pnas.org/cgi/content/full/97/25/13464/F2

  3. Dystrophin Glycoprotein Complex Schematic representation of the dystrophin-associated glycoprotein complex. The N-terminal, actin-binding domain of dystrophin in purple is associated with the cortical actin. The C-terminal domain associates with b-dystroglycan and with a- and b-syntrophin and dystrobrevin. nNOS is known to interact with the syntrophins as well as with caveolin. http://www.pnas.org/cgi/content/full/97/25/13464/F1

  4. Contraction Units http://cellbio.annualreviews.org/cgi/content/full/18/1/637

  5. Cytoskeletal Linkages at Sarcolemma http://cellbio.annualreviews.org/cgi/content/full/18/1/637

  6. Muscle Proteins and Diseases http://www-ermm.cbcu.cam.ac.uk/0200488Xh.htm

  7. contents spill out detected in blood Creatine Kinase and CKI • CKtotal 0-220 U/L CKMB 0-5 ng/mL • Muscle damage CKtotal elevated • CK index (CKI) = CKMB/CKtotal (x 100 for %) • Skeletal origin CKI <0.03 (3%) or use CKMM • Cardiac origin CKI >0.06 (6%) • If 0.03 (3%) > CKI <0.05 (5%) follow with Tn biomarkers Cell damage

  8. In Situ Dystrophin • Normal dystrophin staining around the rim of muscle fibers Absent dystrophin: Duchenne muscular dystrophy • Left: No staining around the rim of muscle fibers. • Right: No staining of most muscle fibers. One "revertant" fiber with dystrophin staining. http://www.neuro.wustl.edu/neuromuscular/pathol/dmdpath.htm

  9. Western Blots • Lane 3: Normal; Dystrophin has normal size and amount. • Lane 1: Becker dystrophy; Dystrophin has reduced abundance but normal size. • Lane 2: Becker dystrophy; Dystrophin has reduced size and abundance. • Lane 4: Duchenne dystrophy; Almost no protein is present. • Lane 5: Duchenne outlier; Dystrophin has severely reduced abundance. Western blot of dystrophin from dystrophinopathies. http://www.neuro.wustl.edu/neuromuscular/pathol/dmdpath.htm

  10. Review Questions • What is dystrophin (domains, characteristics)? • Where is dystrophin found (interactions, role)? • How do you assess muscle damage? • How do you assess dystrophin levels?

More Related