ZFIN ID: ZDB-PUB-090217-35
skNAC (skeletal Naca), a muscle-specific isoform of Naca (nascent polypeptide-associated complex alpha), is required for myofibril organization
Li, H., Randall, W.R., and Du, S.J.
Date: 2009
Source: FASEB journal : official publication of the Federation of American Societies for Experimental Biology   23(6): 1988-2000 (Journal)
Registered Authors: Du, Shao Jun (Jim)
Keywords: none
MeSH Terms:
  • Animals
  • Gene Expression Regulation, Developmental
  • Gene Knockdown Techniques
  • Humans
  • In Situ Hybridization
  • Molecular Chaperones/genetics
  • Molecular Chaperones/metabolism*
  • Morphogenesis/physiology
  • Muscle, Skeletal/cytology
  • Muscle, Skeletal/physiology*
  • Myofibrils/metabolism*
  • Oligonucleotides, Antisense/genetics
  • Oligonucleotides, Antisense/metabolism
  • Protein Isoforms/genetics
  • Protein Isoforms/metabolism*
  • Zebrafish*/anatomy & histology
  • Zebrafish*/embryology
  • Zebrafish*/metabolism
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 19211926 Full text @ FASEB J.
Myofibrillogenesis, the precise assembly of sarcomeric proteins into the highly organized sarcomeres, is essential for muscle cell differentiation and function. Myofibrillogenesis requires proper folding and assembly of newly synthesized sarcomeric proteins. sknac (skeletal naca) is an alternatively spliced isoform of naca, which encodes the nascent polypeptide-associated complex alpha polypeptide that binds to newly synthesized polypeptides emerging from the ribosome. sknac is specifically expressed in skeletal and cardiac muscles. However, little is known about the function of skNAC in muscle development in vivo. To determine skNAC function, we have isolated and characterized the sknac gene from zebrafish. Zebrafish sknac cDNA differs from naca by containing an extra large exon that encodes 815 aa. Knockdown of sknac expression by antisense oligos resulted in zebrafish embryos with skeletal muscle defects. The sknac-knockdown embryos showed a paralyzed phenotype with little muscle contraction. In contrast, injection of a control oligo had no effect. Immunostaining and histological analyses revealed that sknac-knockdown embryos contained disorganized thick and thin filaments. Western blot analysis revealed that myosin protein levels were significantly reduced. Collectively, these results demonstrate that skNAC plays a vital role in myofibril assembly and function during muscle cell differentiation.-Li, H., Randall, W. R., Du, S.-J. skNAC (skeletal Naca), a muscle-specific isoform of Naca (nascent polypeptide-associated complex alpha), is required for myofibril organization in zebrafish embryo.