| First Author | Chew CS | Year | 2008 |
| Journal | Am J Physiol Gastrointest Liver Physiol | Volume | 295 |
| Issue | 1 | Pages | G37-G44 |
| PubMed ID | 18483181 | Mgi Jnum | J:137526 |
| Mgi Id | MGI:3801199 | Doi | 10.1152/ajpgi.90247.2008 |
| Citation | Chew CS, et al. (2008) Targeted disruption of the Lasp-1 gene is linked to increases in histamine-stimulated gastric HCl secretion. Am J Physiol Gastrointest Liver Physiol 295(1):G37-G44 |
| abstractText | Lasp-1 (LIM and SH3 domain protein 1) is a multidomain actin-binding protein that is differentially expressed within epithelial tissues and brain. In the gastric mucosa, Lasp-1 is highly expressed in the HCl-secreting parietal cell, where it is prominently localized within the F-actin-rich subcellular regions. Histamine-induced elevation of parietal cell [cAMP]i increases Lasp-1 phosphorylation, which is correlated with activation of HCl secretion. To determine whether Lasp-1 is involved in the regulation of HCl secretion in vivo, we generated a murine model with a targeted disruption of the Lasp-1 gene. Lasp-1-null mice had slightly lower body weights but developed normally and had no overt phenotypic abnormalities. Basal HCl secretion was unaffected by loss of Lasp-1, but histamine stimulation induced a more robust acid secretory response in Lasp-1-null mice compared with wild-type littermates. A similar effect of histamine was observed in isolated gastric glands on the basis of measurements of accumulation of the weak base [14C]aminopyrine. In addition, inhibition of the acid secretory response to histamine by H2 receptor blockade with ranitidine proceeded more slowly in glands from Lasp-1-null mice. These findings support the conclusion that Lasp-1 is involved in the regulation of parietal HCl secretion. We speculate that cAMP-dependent phosphorylation of Lasp-1 alters interactions with F-actin and/or endocytic proteins that interact with Lasp-1, thereby regulating the trafficking/activation of the H+, K+-ATPase (proton pump). |
