Gs and Gi protein subunits during cell differentiation in intestinal crypt-villus axis: regulation at the mRNA level.
The expression of subunits of the guanine nucleotide regulatory protein that mediates hormonal stimulation of adenylyl cyclase (Gs) and of the guanine nucleotide regulatory protein that mediates hormonal inhibition of adenylyl cyclase (Gi) was studied during cell migration and differentiation in the rat small intestine crypt-villus axis. Proliferative crypt cells were separated from nonproliferative mature villus cells and the following data were obtained: 1) alpha s subunits were more abundant in crypt cells than in villus cells as evidenced by cholera toxin-catalyzed [32P]NAD ribosylation and Western blotting of this relative molecular weight (M(r)) 42,000 protein; 2) alpha i2- and alpha i3-subunits (M(r) 40,000 and M(r) 41,000, respectively) were preferentially expressed in villus cells as evidenced by pertussis toxin-catalyzed [32P]NAD ribosylation and Western blotting (alpha i1-subunit was not detectable in intestinal epithelium by using these techniques); 3) Western blotting showed a higher expression of the common beta- (M(r) 36,000) subunit of G proteins in villus cells than in crypt cells; and 4) Northern blot analysis using an alpha s-subunit oligonucleotide probe showed a 1.9-kb mRNA that was more abundant in crypt cells than in villus cells. In contrast, alpha i2- and alpha i3-mRNA species (2.3 and 3.5 kb, respectively), analyzed by using specific cDNA probes, were much more abundant in villus cells than in crypt cells. Finally, two beta-subunit mRNA species of 3.3 and 1.8 kb were detectable in intestinal epithelial cells and were more abundant in villus cells than in crypt cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Couvineau
A
A
Institut National de la Santé et de la Recherche Médicale (INSERM) U. 239, Faculté de Médecine X. Bichat, Paris, France.
Darmoul
D
D
Blais
A
A
Rouyer-Fessard
C
C
Daviaud
D
D
Voisin
T
T
Paris
H
H
Rouot
B
B
Laburthe
M
M
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D037361:Adenylate Cyclase Toxin; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002454:Cell Differentiation; D002772:Cholera Toxin / Q000494:pharmacology; D018819:Dipeptidyl Peptidase 4; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005786:Gene Expression Regulation; D007413:Intestinal Mucosa / Q000166:cytology / Q000502:physiology*; D007583:Jejunum / Q000166:cytology / Q000502:physiology; D046911:Macromolecular Substances; D008297:Male; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D037342:Pertussis Toxin; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013393:Sucrase / Q000378:metabolism; D014158:Transcription, Genetic; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D046911:Macromolecular Substances; D008565:Membrane Proteins; D012333:RNA, Messenger; D010566:Virulence Factors, Bordetella; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D012313:RNA; D002772:Cholera Toxin; D037342:Pertussis Toxin; D000469:Alkaline Phosphatase; D013393:Sucrase; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4; D019204:GTP-Binding Proteins