Immunohistochemical study of the membrane skeletal protein, membrane protein palmitoylated 6 (MPP6), in the mouse small intestine.
The membrane protein palmitoylated (MPP) family belongs to the membrane-associated guanylate kinase (MAGUK) family. MPP1 interacts with the protein 4.1 family member, 4.1R, as a membrane skeletal protein complex in erythrocytes. We previously described the interaction of another MPP family, MPP6, with 4.1G in the mouse peripheral nervous system. In the present study, the immunolocalization of MPP6 in the mouse small intestine was examined and compared with that of E-cadherin, zonula occludens (ZO)-1, and 4.1B, which we previously investigated in intestinal epithelial cells. The immunolocalization of MPP6 was also assessed in the small intestines of 4.1B-deficient (-/-) mice. In the small intestine, Western blotting revealed that the molecular weight of MPP6 was approximately 55-kDa, and MPP6 was immunostained under the cell membranes in the basolateral portions of almost all epithelial cells from the crypts to the villi. The immunostaining pattern of MPP6 in epithelial cells was similar to that of E-cadherin, but differed from that of ZO-1. In intestinal epithelial cells, the immunostained area of MPP6 was slightly different from that of 4.1B, which was restricted to the intestinal villi. The immunolocalization of MPP6 in small intestinal epithelial cells was similar between 4.1B(-/-) mice and 4.1B(+/+) mice. In the immunoprecipitation study, another MAGUK family protein, calcium/calmodulin-dependent serine protein kinase (CASK), was shown to molecularly interact with MPP6. Thus, we herein showed the immunolocalization and interaction proteins of MPP6 in the mouse small intestine, and also that 4.1B in epithelial cells was not essential for the sorting of MPP6.
Division of Health Sciences, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto City, Nagano, 390-8621, Japan.
Akio
A
Kamijo
Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo City, Yamanashi, 409-3898, Japan.
Yurika
Y
Saitoh
Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo City, Yamanashi, 409-3898, Japan.
Nobuhiko
N
Ohno
Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo City, Yamanashi, 409-3898, Japan.
Shinichi
S
Ohno
Division of Health Sciences, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto City, Nagano, 390-8621, Japan. nobuot@shinshu-u.ac.jp.
Nobuo
N
Terada
D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D051528:Guanylate Kinases / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism*; D058635:Lipid-Linked Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
D015820:Cadherins; C488402:Epb41l3 protein, mouse; D058635:Lipid-Linked Proteins; C569941:MPP6 protein, mouse; D008565:Membrane Proteins; D008840:Microfilament Proteins; C569043:Tjp1 protein, mouse; D062826:Zonula Occludens-1 Protein; C106868:CASK kinases; D051528:Guanylate Kinases
Membrane protein palmitoylated; Membrane skeleton; Membrane-associated guanylate kinase; Small intestine