Co-distribution of calmodulin-dependent protein kinase II and inositol trisphosphate receptors in an apical domain of gastrointestinal mucosal cells

• Published in: The journal of histochemistry and cytochemistry Vol. 44; no. 11; pp. 1243 - 1250
• Main Authors: Matovcik, LM, Maranto, AR, Soroka, CJ, Gorelick, FS, Smith, J, Goldenring, JR
• Format: Journal Article
• Language: English
• Published: United States Histochemical Soc 01-11-1996; SAGE Publications
• Subjects: Animals; Calcium Channels - analysis; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Calcium-Calmodulin-Dependent Protein Kinases - analysis; Cell Polarity; Digestive System - metabolism; Fluorescent Antibody Technique, Indirect; Inositol 1,4,5-Trisphosphate - metabolism; Inositol 1,4,5-Trisphosphate Receptors; Intestinal Mucosa - cytology; Intestinal Mucosa - metabolism; Male; Rabbits; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear - analysis
• ISSN: 0022-1554; 1551-5044
• DOI: 10.1177/44.11.8918899

The Type 3 inositol 1,4,5-trisphosphate (InsP3) receptor is expressed at high levels
in gastrointestinal tissues. This receptor has 16 potential phosphorylation sites for
calcium/calmodulin-dependent protein kinase II (CaM kinase II). To determine if the
Type 3 InsP3 receptor is likely to be a physiologic substrate for CaM kinase II,
localizations of the Type 3 InsP3 receptor and CaM kinase II were compared in tissues
of the gastrointestinal tract. Cellular and subcellular localizations were determined
by immunofluorescence microscopy in rat intestine, pancreas, and stomach, and in
isolated rabbit gastric glands. Both proteins were found in the apical region of
intestinal enterocytes, pancreatic acinar cells, and gastric parietal, chief, and
surface mucous cells. CaM kinase II was found throughout the entire intracellular
canalicular F-actin domain of parietal cells, whereas the type 3 InsP3 receptor was
restricted to the neck region. Thus, in several gastrointestinal tissues the Type 3
InsP3 receptor is specifically localized to a portion of the apical cytoskeletal
domain in which resides the calcium-responsive effector CaM kinase II.