PUBLICATION
Identification of a novel tropomodulin isoform, skeletal tropomodulin, that caps actin filament pointed ends in skeletal muscle
- Authors
- Almenar-Queralt, A., Lee, A., Conley, C.A., Ribas-Pouplana, L., and Fowler, V.M.
- ID
- ZDB-PUB-000406-1
- Date
- 1999
- Source
- The Journal of biological chemistry 274(40): 28466-28475 (Journal)
- Registered Authors
- Conley, Catharine A.
- Keywords
- none
- MeSH Terms
-
- Tropomodulin
- Muscle Development
- Chickens
- Protein Isoforms/genetics
- Protein Isoforms/metabolism*
- Spectrin/metabolism
- Base Sequence
- DNA, Complementary
- Chick Embryo
- Actins/metabolism*
- Carrier Proteins/genetics
- Carrier Proteins/metabolism*
- Microfilament Proteins*
- Animals
- Molecular Sequence Data
- Muscle, Skeletal/growth & development
- Muscle, Skeletal/metabolism*
- Sequence Homology, Amino Acid
- Amino Acid Sequence
- PubMed
- 10497209 Full text @ J. Biol. Chem.
Citation
Almenar-Queralt, A., Lee, A., Conley, C.A., Ribas-Pouplana, L., and Fowler, V.M. (1999) Identification of a novel tropomodulin isoform, skeletal tropomodulin, that caps actin filament pointed ends in skeletal muscle. The Journal of biological chemistry. 274(40):28466-28475.
Abstract
Tropomodulin (E-Tmod) is an actin filament pointed end capping protein that maintains the length of the sarcomeric actin filaments in striated muscle. Here, we describe the identification and characterization of a novel tropomodulin isoform, skeletal tropomodulin (Sk-Tmod) from chickens. Sk-Tmod is 62% identical in amino acid sequence to the previously described chicken E-Tmod and is the product of a different gene. Sk-Tmod isoform sequences are highly conserved across vertebrates and constitute an independent group in the tropomodulin family. In vitro, chicken Sk-Tmod caps actin and tropomyosin-actin filament pointed ends to the same extent as does chicken E-Tmod. However, E- and Sk-Tmods differ in their tissue distribution; Sk-Tmod predominates in fast skeletal muscle fibers, lens, and erythrocytes, while E-Tmod is found in heart and slow skeletal muscle fibers. Additionally, their expression is developmentally regulated during chicken breast muscle differentiation with Sk-Tmod replacing E-Tmod after hatching. Finally, in skeletal muscle fibers that coexpress both Sk- and E-Tmod, they are recruited to different actin filament-containing cytoskeletal structures within the cell: myofibrils and costameres, respectively. All together, these observations support the hypothesis that vertebrates have acquired different tropomodulin isoforms that play distinct roles in vivo.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping