Rab11 is an apically located small gtp-binding protein in epithelial tissues. Goldenring, James R., Jenetta Smith, Hilary D. Vaughan, Patricia Cameron, Wendy Hawkins, Jennifer Navarre. Departments of Medicine, Cellular Biology and Anatomy, and Surgery, Institute for Molecular Medicine and Genetics Medical College of Georgia and the Augusta VA Medical Center, Augusta, Georgia 30912
APStracts 2:0183G, 1995.
Rab proteins are involved in many aspects of dynamic vesicle processing within eukaryotic cells. We have previously identified Rab11 in gastric parietal cell tubulovesicle membranes. We have produced a monoclonal antibody which is specific for Rab11. In all rabbit tissues examined, Rab11 immunoreactivity was highly enriched in epithelial cells. In the gastric fundus, parietal cells were stained in a pattern consistent with localization on tubulovesicles. Surface mucous cells of both the fundus and antrum demonstrated punctate sub-apical staining. Ileal and proximal colonic enterocyte labelling was observed deep to the brush borders. In the distal colon, staining was observed in the apical regions of mid-crypt cells. In skin and esophagus, punctate immunoreactivity was present in the medial layers of the squamous epithelia. Prominent Rab11 immunoreactivity was present in hepatocytes deep to the bile canaliculi. Punctate sub-apical staining was observed in pancreatic acinar cells. Apical staining was also observed in collecting duct cells and in the glandular cells of the prostate. These results indicate that Rab11 is expressed in apical vesicular populations in discrete epithelial cell populations. 

Received 1 February 1995; accepted in final form 30 August 1995.
APS Manuscript Number G47-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.