title: Localization of a novel GAP family protein SPAL in the rat esophagus and heart.
abstract: Spa-1-like protein (SPAL) is a novel GTPase-activating protein (GAP) family protein. We generated anti-SPAL antibody, and examined localization of SPAL in the rat esophagus and heart by immunofluorescence microscopy. In the esophagus, SPAL was highly expressed in the spinous and granular layers and localized at the cell-cell border of the epithelial cells. SPAL in the spinous layer was almost colocalized with beta-catenin, an intracellular anchor protein of E-cadherin, while colocalization of SPAL with the tight junction protein ZO-1 was shown in the granular layer. In the heart, SPAL was localized at the intercalated disks, and there colocalized with both beta-catenin and ZO-1. In addition, much punctate localization of SPAL was seen along lateral borders of the cardiomyocytes, where beta-catenin and ZO-1 were absent. From these results, it is suggested that SPAL may regulate cell-cell adhesion in the rat esophagus and heart.
authors.affiliation: Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Badal C.
authors.initials: BC
authors.lastname: Roy
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kuroda
authors.forename: Shigeo
authors.initials: S
authors.lastname: Mori
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kohu
authors.forename: Tetsu
authors.initials: T
authors.lastname: Akiyama
authors.forename: T.
authors.initials: T
authors.lastname: Senda