title: Morphogenesis of T-tubules in heart cells: the role of junctophilin-2.
abstract: The T-tubule (TT) system forms the structural basis for excitation-contraction coupling in heart and muscle cells. The morphogenesis of the TT system is a key step in the maturation of heart cells because it does not exist in neonatal cardiomyocytes. In the present study, we quantified the morphological changes in TTs during heart cell maturation and investigated the role of junctophilin-2 (JP2), a protein known to anchor the sarcoplasmic reticulum (SR) to TT, in changes to TT morphological parameters. Analysis of confocal images showed that the transverse elements of TTs increased, while longitudinal elements decreased during the maturation of TTs. Fourier transform analysis showed that the power of ∼2 μm spatial components increased with cardiomyocytes maturation. These changes were preceded by increased expression of JP2, and were reversed by JP2 knockdown. These findings indicate that JP2 is required for the morphogenesis of TTs during heart development.
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.forename: Haodi
authors.initials: H
authors.lastname: Wu
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Wang
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000378:metabolism; D005583:Fourier Analysis; D006321:Heart / Q000254:growth & development; D006352:Heart Ventricles / Q000166:cytology / Q000254:growth & development; D007091:Image Processing, Computer-Assisted; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology*; D018613:Microscopy, Confocal; D009024:Morphogenesis / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D013997:Time Factors
chemical_list: D008565:Membrane Proteins; C412507:junctophilin