GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:19807849

From GONUTS
Jump to: navigation, search
Citation

Roncero, I, Sanz, C, Alvarez, E, Vázquez, P, Barrio, PA and Blázquez, E (2009) Glucokinase and glucokinase regulatory proteins are functionally coexpressed before birth in the rat brain. J. Neuroendocrinol. 21:973-81

Abstract

Our previous description of functional glucokinase (GK) isoforms and their interactions with glucokinase regulatory protein (GKRP) in adult rat and human brains suggested that both participate in glucose sensing in the central nervous system. To determine whether both proteins are coexpressed and active before birth or during early post-natal life, we characterised these molecules in the brains of foetal and post-natal pup rats. We found GK and GKRP mRNAs that were similar to those previously reported in the adult rat brain. Likewise, GK and GKRP gene expression gave rise to proteins of 52 and 69 kDa, respectively. Immunohistochemistry experiments showed the colocalisation of both GK and GKRP proteins in the same brain cells of 21-day-old rat foetuses. Furthermore, coprecipitation of GK and GKRP in the presence of fructose 6-phosphate suggests interactions between both proteins. The presence of GK phosphorylating activity was detected in different brain areas of 21-day-old foetuses with a contribution to the total glucose-phosphorylating activity of between 17.2 +/- 1.7% and 12.4 +/- 3.7%, with the hypothalamus being the region of maximum activity. The hypothalamic GK activity in 21-day-old foetuses has a high apparent K(m) for glucose and no product inhibition by glucose 6-phosphate. Our findings indicate that both proteins may be functionally active before birth and that they can act within a glucose sensor system involved in controlling food intake.

Links

PubMed Online version:10.1111/j.1365-2826.2009.01919.x

Keywords

Animals; Animals, Newborn; Blotting, Western; Brain/embryology; Brain/growth & development; Brain/metabolism; Carrier Proteins/metabolism; Female; Fructosephosphates/metabolism; Glucokinase/metabolism; Glucose/metabolism; Hypothalamus/embryology; Hypothalamus/growth & development; Hypothalamus/metabolism; Immunohistochemistry; Kinetics; Liver/metabolism; Male; Phosphorylation; RNA, Messenger/metabolism; Rats; Rats, Wistar; Spectrophotometry

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

RAT:HXK4

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:Q07071

F

Seeded From UniProt

complete

RAT:GCKR

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:P17712

F

Seeded From UniProt

complete

RAT:HXK4

involved_in

GO:0051594: detection of glucose

ECO:0000303: author statement without traceable support used in manual assertion

P

Seeded From UniProt

complete

RAT:GCKR

involved_in

GO:0051594: detection of glucose

ECO:0000303: author statement without traceable support used in manual assertion

P

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.