Nebulette: a 107 kD nebulin-like protein in cardiac muscle

Cell Motil Cytoskeleton. 1995;32(3):205-25. doi: 10.1002/cm.970320305.

Abstract

A 107-kD protein has been identified in primary cultures of chicken embryonic cardiomyocytes by immunoprecipitations with certain anti-nebulin monoclonal antibodies (mAbs). These mAbs, prepared against a fragment of human skeletal muscle nebulin located near the carboxyl terminus, detect a 107-kD protein in extracts of adult chicken heart, adult mouse heart, and adult rabbit heart by immunoblot analysis. A partial cDNA corresponding to this protein has been isolated by immunological screening of a chicken heart cDNA expression vector library. The partial cDNA encodes a 380-amino acid open reading frame composed entirely of nebulin-like 35-residue modules marked by the highly conserved sequence motifs: SXXXYK and TPD. The open reading frame exhibits 60-85% homology with skeletal muscle nebulins from a variety of species. This cDNA recognizes an approximately 8-kb transcript in cardiac RNA and does not hybridize to skeletal muscle RNAs by northern analysis. Immunofluorescence localization of this nebulin-like protein in primary cultures of chicken cardiomyocytes and embryonic chicken cardiac myofibrils indicates that the protein is localized to the I-Z-I complex of the myofibrils, extending approximately 25% of the thin filament length. Comparisons of the distribution of this protein relative to actin, myosin, and titin in spreading cardiomyocytes suggest that the cardiac nebulin-like protein becomes aligned with the nascent myofibrils early during myofibrillogenesis. To distinguish this petite nebulin-like protein from the 600-900 kD skeletal muscle nebulin, we have named it nebulette.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Antibody Specificity
  • Base Sequence
  • Carrier Proteins
  • Cells, Cultured / physiology
  • Chick Embryo
  • Cross Reactions
  • Cytoskeletal Proteins
  • DNA, Complementary / genetics
  • Gene Library
  • Genetic Testing
  • Humans
  • Immunoblotting
  • LIM Domain Proteins
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Molecular Weight
  • Muscle Proteins / analysis*
  • Muscle Proteins / genetics*
  • Muscle Proteins / immunology
  • Muscle, Skeletal / chemistry
  • Myocardium / chemistry*
  • Myocardium / cytology
  • Myofibrils / chemistry
  • Rabbits
  • Sarcomeres / chemistry
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid

Substances

  • Antibodies, Monoclonal
  • Carrier Proteins
  • Cytoskeletal Proteins
  • DNA, Complementary
  • LIM Domain Proteins
  • Muscle Proteins
  • NEBL protein, human
  • Nebl protein, mouse
  • nebulin

Associated data

  • GENBANK/U35276