PMID:9295142

Citation	Luo, G, Zhang, JQ, Nguyen, TP, Herrera, AH, Paterson, B and Horowits, R (1997) Complete cDNA sequence and tissue localization of N-RAP, a novel nebulin-related protein of striated muscle. Cell Motil. Cytoskeleton 38:75-90
Abstract	We have cloned and sequenced the full-length cDNA of N-RAP, a novel nebulin-related protein, from mouse skeletal muscle. The N-RAP message is specifically expressed in skeletal and cardiac muscle, but is not detected by Northern blot in non-muscle tissues. The full-length N-RAP cDNA contains an open reading frame of 3,525 base pairs which is predicted to encode a protein of 133 kDa. A 587 amino acid region near the C-terminus is 45% identical to the actin binding region of human nebulin, containing more than 2 complete 245 residue nebulin super repeats. The N-terminus contains the consensus sequence of a cysteine-rich LIM domain, which may function in mediating protein-protein interactions. These data suggest that the encoded protein may link actin filaments to some other proteins or structure. We expressed full-length N-RAP in Escherichia coli, as well as the nebulin-like super repeat region of N-RAP (N-RAP-SR) and the region between the LIM domain and N-RAP-SR (N-RAP-IB). An anti-N-RAP antibody raised against a 30 amino acid peptide corresponding to sequence from N-RAP-IB detected recombinant N-RAP and N-RAP-IB, but failed to detect N-RAP-SR. This antibody specifically identified a 185 kDa band as N-RAP on immunoblots of mouse skeletal and cardiac muscle proteins. In an assay of actin binding to electrophoresed and blotted proteins, we detected significant actin binding to expressed nebulin super repeats and N-RAP-SR, but only a trace amount of binding to N-RAP-IB. In immunofluorescence experiments, N-RAP was found to be localized at the myotendinous junction in mouse skeletal muscle and at the intercalated disc in cardiac muscle. Based on its domain organization, actin binding properties, and tissue localization, we propose that N-RAP plays a role in anchoring the terminal actin filaments in the myofibril to the membrane and may be important in transmitting tension from the myofibrils to the extracellular matrix.
Links	PubMed Online version:<75::AID-CM7>3.0.CO;2-G 10.1002/(SICI)1097-0169(1997)38:1<75::AID-CM7>3.0.CO;2-G
Keywords	Actins/metabolism; Amino Acid Sequence; Animals; Base Sequence; Cloning, Molecular; DNA, Complementary/genetics; Humans; Mice; Molecular Sequence Data; Muscle Proteins/analysis; Muscle Proteins/genetics; Muscle Proteins/metabolism; Muscle, Skeletal/chemistry; Myocardium/chemistry; Open Reading Frames/genetics; Organ Specificity; RNA, Messenger/analysis; Recombinant Proteins/metabolism; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid
edit table

Annotations

Gene product	Qualifier	GO ID	GO term name	Evidence Code	with/from	Aspect	Notes	Status
edit table

References

See Help:References for how to manage references in GONUTS.