scholarly journals The inhibitory guanine nucleotide-binding regulatory component of adenylate cyclase. Properties and function of the purified protein.

1984 ◽  
Vol 259 (6) ◽  
pp. 3568-3577 ◽  
Author(s):  
T Katada ◽  
G M Bokoch ◽  
J K Northup ◽  
M Ui ◽  
A G Gilman
Keyword(s):  
Adenylate Cyclase ◽  
Nucleotide Binding ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding ◽  
And Function

Forskolin stimulation of adenylate cyclase in human thyroid membranes

1985 ◽  
Vol 108 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Kikuo Kasai ◽  
Yoshinobu Suzuki ◽  
Masaki Hiraiwa ◽  
Hisamoto Kuroda ◽  
Tatsushi Emoto ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Nucleotide Binding ◽  
Guanine Nucleotides ◽  
Human Thyroid ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding ◽  
Stimulation Of

Abstract. Forskolin stimulates adenylate cyclase in human thyroid membranes approximately 7-fold with halfmaximal stimulation occurring at 5–10 μm. Guanine nucleotides are not required for stimulation of the enzyme by forskolin. Forskolin-stimulation is additive or greater than additive with that of TSH or Gpp(NH)p-(above 1 μm). Different from TSH- or Gpp(NH)p-stimulation of adenylate cyclase, uncoupling of the guanine nucleotide-binding regulatory component by increasing concentrations of MnCl2 did not result in uncoupling of forskolin stimulation. The finding indicates that forskolin may mainly act on the catalytic component of adenylate cyclase. From the present study, it is suggested that the diterpene forskolin stimulates adenylate cyclase in human thyroid membranes by a novel mechanism that differs from TSH- or Gpp(NH)p-stimulation, and that the diterpene may be a useful tool to investigate the metabolism of thyroid and its regulation in normal and pathological situations.

scholarly journals Antibody of predetermined specificity to a carboxy-terminal region of H-ras gene products inhibits their guanine nucleotide-binding function.

1985 ◽  
Vol 5 (11) ◽  
pp. 3316-3319 ◽  
Author(s):  
S K Srivastava ◽  
J C Lacal ◽  
S H Reynolds ◽  
S A Aaronson
Keyword(s):  
Nucleotide Binding ◽  
Terminal Region ◽  
Guanine Nucleotide ◽  
Ras Gene ◽  
P21 Protein ◽  
Binding Function ◽  
Carboxy Terminal Region ◽  
Guanine Nucleotide Binding ◽  
Carboxy Terminal ◽  
And Function

The high prevalence of ras oncogenes in human tumors has given increasing impetus to efforts aimed at elucidating the structure and function of their p21 products. To identify functionally important domains of the p21 protein, antibodies were generated against synthetic peptides corresponding to various regions of the protein. Antibodies directed against a synthetic peptide fragment corresponding to amino acid residues 161 to 176 in the carboxy-terminal region of the H-ras-encoded p21 molecule specifically recognized H-ras-encoded p21 proteins. This antibody was also shown to strikingly and specifically inhibit the guanine nucleotide-binding function of the p21 protein. The inability of p21 protein to bind guanine nucleotides was associated with a lack of autophosphorylation or GTPase activities. These studies suggest that a region toward its carboxy terminus is directly or indirectly involved in the guanine nucleotide-binding function of the p21 molecule.

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