Antibodies raised against a peptide corresponding to a Gs alpha domain reveal a vimentin-associated protein

• Published in: The journal of histochemistry and cytochemistry Vol. 41; no. 5; pp. 709 - 717
• Main Authors: Anglade, G, Dupouey, P, Ensergueix, D, Ceard, B, Monneron, A
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Histochemical Soc 01.05.1993; SAGE Publications; Histochemical Society
• Subjects: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Biological and medical sciences; Blotting, Western; Brain Chemistry; Cerebellum - chemistry; Cytoskeleton - chemistry; Diverse techniques; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; GTP-Binding Proteins - analysis; Haplorhini; Humans; Immunoenzyme Techniques; Mice; Molecular and cellular biology; Molecular Sequence Data; Molecular Weight; Rats; Rats, Wistar; Vimentin - analysis; Cerebellum; Immunohistochemistry; Proteins; Vimentin; Vertebrata; Mammalia; Rat; Mouse; Rodentia; Central nervous system; Cytoskeleton; Localization
• ISSN: 0022-1554; 1551-5044
• DOI: 10.1177/41.5.8468452

In an attempt to localize the guanine nucleotide binding protein Gs alpha by immunocytochemistry, we synthetized peptides corresponding to several stretches of residues deduced from the published cDNA sequence of Gs alpha and raised antibodies against them. Among the peptides, one corresponding to residues 367-381 elicited antibodies that immunocytochemically detected, at the optical level, what appeared to be vimentin in several cells and tissues. Studies at the ultrastructural level confirmed this observation and also showed weak staining of some areas of plasma membranes of glial and nerve cells. Analysis by Western blots of rat brain subcellular fractions indicated that: (a) the protein stained by the anti-peptide antibodies was associated with the cytoskeleton; and (b) it was not vimentin but a protein of higher molecular weight, 65 KD. We accordingly suggest that the Gs alpha-derived peptide elicited two types of antibodies, one recognizing Gs alpha in fixed tissues, the other recognizing an epitope located in a vimentin-associated protein. This study emphasizes the caution that is needed when conclusions are drawn on the basis of immunocytochemical studies using antipeptide antibodies.