Peer-Reviewed Journal Details
Mandatory Fields
Peckham, M.,Young, P.,Gautel, M.;
1997
Constitutive and variable regions of Z-disk titin/connectin in myofibril formation: a dominant-negative screen
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Optional Fields
22
1
95
101.
The giant muscle protein titin (connectin) is assumed to play a crucial role in the control of Z-disk assembly. Analysis of the Z-disk region of titin/connectin revealed a novel 45 residue repeat that is spliced in variable copy numbers. The repeat region is coexpressed in normal human myocardium in size variants corresponding to between 5 and 7 repeats. Smaller isoforms can be detected in muscles with thinner Z- disks like M. psoas. Sequence analysis of chicken breast muscle titin/connectin reveals that in this tissue, where Z-disks are thin, only two Z-repeats are expressed. The greatly variable thickness of Z- disks is therefore correlated to a region of variable length in titin/connectin, constructed from a novel protein building block. Transfection experiments in myogenic cell lines demonstrate that overexpression of the entire integral Z-disk region of titin leads to a disruption of sarcomere assembly. The differentially expressed titin/connectin regions, however, show no dominant-negative effects on myofibril assembly and are not targeted to Z-disks. This supports the idea that the Z-repeat region of titin/connectin is responsible for the control Z-disk thickness as an element of highly variable length, due to extensive differential splicing.
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m&form=6&dopt=r&uid=9113395
Grant Details