PMID- 2995376
OWN - NLM
STAT- MEDLINE
DCOM- 19851114
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 260
IP  - 23
DP  - 1985 Oct 15
TI  - Insulin receptor kinase activity in rat liver. Regulation by fasting and high 
      carbohydrate feeding.
PG  - 12444-53
AB  - Insulin receptor kinase activity was measured in partially purified receptor 
      preparations from livers of rats fed a standard diet or subjected to either 
      prolonged fasting or a high carbohydrate (CHO) diet, conditions known to decrease 
      (fasting) and increase (CHO) insulin action. Basal and insulin-stimulated 
      phosphorylation of the beta subunit of the insulin receptor was comparable in all 
      groups with a half-maximal effect at approximately 2.0 ng/ml free insulin and a 
      10-12-fold maximal effect. The kinase activity of insulin receptors from the 
      three groups was further examined using the synthetic polypeptide Glu 4:Tyr 1. 
      Basal and insulin-stimulated rates of Glu 4:Tyr 1 phosphorylation were highest in 
      the CHO-fed and lowest in the fasted group. The magnitude of these differences 
      was the same in the absence or presence of insulin; thus, the alterations in 
      receptor kinase activity in fasting and CHO feeding were entirely expressed in 
      the basal rate of peptide phosphorylation. Antireceptor antibody 
      immunoprecipitated 70-80% of the basal Glu 4:Tyr 1 kinase activity in each group; 
      the remaining 20-30% showed minor group differences when normalized for the 
      amount of protein present in the receptor preparations. These results indicate 
      that the group differences in basal kinase were intrinsic to the insulin 
      receptor. Insulin increased the Vmax of Glu 4:Tyr 1 phosphorylation by 
      approximately 30 fmol of phosphorus/fmol of binding activity/30 min in all three 
      groups; however, the absolute Vmax was highest in the CHO-fed and lowest in the 
      fasted group. The Km of Glu 4:Tyr 1 phosphorylation was unaffected by insulin and 
      was comparable (approximately 0.25 mg/ml) in the three groups. These findings 
      indicate that fasting and CHO feeding produce changes in receptor kinase activity 
      which are regulated by mechanisms independent of insulin and that the alterations 
      show substrate specificity so that differences are detected with one substrate 
      (Glu 4:Tyr 1) but not another (the beta subunit).
FAU - Freidenberg, G R
AU  - Freidenberg GR
FAU - Klein, H H
AU  - Klein HH
FAU - Cordera, R
AU  - Cordera R
FAU - Olefsky, J M
AU  - Olefsky JM
LA  - eng
GR  - AM 07494/AM/NIADDK NIH HHS/United States
GR  - AM 33650/AM/NIADDK NIH HHS/United States
GR  - AM 33651/AM/NIADDK NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Insulin)
RN  - 0 (Intercellular Signaling Peptides and Proteins)
RN  - 0 (Peptides)
RN  - 31325-39-0 (L-glutamic acid-L-tyrosine copolymer)
RN  - EC 2.7.10.1 (Protein-Tyrosine Kinases)
RN  - EC 2.7.10.1 (Receptor, Insulin)
RN  - EC 3.6.1.- (Adenosine Triphosphatases)
SB  - IM
MH  - Adenosine Triphosphatases/metabolism
MH  - Animals
MH  - Dietary Carbohydrates/*pharmacology
MH  - *Fasting
MH  - Immunosorbent Techniques
MH  - Insulin/pharmacology
MH  - Intercellular Signaling Peptides and Proteins
MH  - Kinetics
MH  - Male
MH  - Microsomes, Liver/*enzymology
MH  - Peptides/metabolism
MH  - Phosphorylation
MH  - Protein-Tyrosine Kinases/*metabolism
MH  - Rats
MH  - Rats, Inbred Strains
MH  - Receptor, Insulin/drug effects/*metabolism
EDAT- 1985/10/15 00:00
MHDA- 1985/10/15 00:01
CRDT- 1985/10/15 00:00
PHST- 1985/10/15 00:00 [pubmed]
PHST- 1985/10/15 00:01 [medline]
PHST- 1985/10/15 00:00 [entrez]
AID - S0021-9258(17)38893-2 [pii]
PST - ppublish
SO  - J Biol Chem. 1985 Oct 15;260(23):12444-53.