PMID- 3013309
OWN - NLM
STAT- MEDLINE
DCOM- 19860801
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 25
IP  - 9
DP  - 1986 May 6
TI  - Characterization of glucagon receptors in Golgi fractions of rat liver: evidence 
      for receptors that are uncoupled from adenylyl cyclase.
PG  - 2612-20
AB  - Glucagon receptors have been identified and characterized in intermediate (Gi) 
      and heavy (Gh) Golgi fractions from rat liver. At saturation, plasma membranes 
      bound 3500 fmol of hormone/mg of membrane protein, while Gi and Gh bound 24 and 
      60 fmol of 125I-glucagon/mg of protein, respectively. Half-maximal saturation of 
      binding to plasma membranes, Gi, and Gh occurred at approximately 4, 10, and 20 
      nM 125I-glucagon, respectively. Trichloroacetic acid precipitation of intact, but 
      not degraded, glucagon was used to correct binding isotherms for hormone 
      degradation. After such correction, half-maximal saturation of binding to plasma 
      membranes, Gi, and Gh was observed in the presence of approximately 2, 7, and 14 
      nM hormone, respectively. After 90 min of dissociation in the absence of 
      guanosine 5'-triphosphate (GTP), 86% of 125I-glucagon remained bound to plasma 
      membranes, whereas only 42% remained bound to Golgi membranes. GTP significantly 
      increased the fraction of 125I-glucagon released from plasma membranes but only 
      slightly augmented the dissociation of hormone from Golgi fractions. 
      125I-Glucagon/receptor complexes solubilized from plasma membranes fractionated 
      by gel filtration as high molecular weight (Kav = 0.16), GTP-sensitive complexes 
      and lower molecular weight (Kav = 0.46), GTP-insensitive complexes. 125I-Glucagon 
      complexes solubilized from Golgi membranes fractionated almost exclusively as the 
      lower molecular weight species. The lower affinity of Golgi than plasma membrane 
      receptors for hormone, the ability of glucagon to stimulate plasma membrane, but 
      not Golgi membrane, adenylyl cyclase, and the near absence of high molecular 
      weight, GTP-sensitive complexes in solubilized Golgi membranes demonstrate that 
      plasma membrane contamination of Golgi fractions cannot account for the 
      125I-glucagon binding.(ABSTRACT TRUNCATED AT 250 WORDS)
FAU - Lipson, K E
AU  - Lipson KE
FAU - Kolhatkar, A A
AU  - Kolhatkar AA
FAU - Cherksey, B D
AU  - Cherksey BD
FAU - Donner, D B
AU  - Donner DB
LA  - eng
GR  - AM 01045/AM/NIADDK NIH HHS/United States
GR  - AM 07112/AM/NIADDK NIH HHS/United States
GR  - AM 22121/AM/NIADDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Receptors, Cell Surface)
RN  - 0 (Receptors, Glucagon)
RN  - 9007-92-5 (Glucagon)
RN  - EC 4.6.1.1 (Adenylyl Cyclases)
SB  - IM
MH  - Adenylyl Cyclases/*metabolism
MH  - Animals
MH  - Cell Membrane/metabolism
MH  - Glucagon/*metabolism
MH  - Golgi Apparatus/*metabolism
MH  - Kinetics
MH  - Liver/*metabolism
MH  - Male
MH  - Microsomes, Liver/metabolism
MH  - Rats
MH  - Rats, Inbred Strains
MH  - Receptors, Cell Surface/*metabolism
MH  - Receptors, Glucagon
EDAT- 1986/05/06 00:00
MHDA- 1986/05/06 00:01
CRDT- 1986/05/06 00:00
PHST- 1986/05/06 00:00 [pubmed]
PHST- 1986/05/06 00:01 [medline]
PHST- 1986/05/06 00:00 [entrez]
AID - 10.1021/bi00357a050 [doi]
PST - ppublish
SO  - Biochemistry. 1986 May 6;25(9):2612-20. doi: 10.1021/bi00357a050.