Signal transduction crosstalk in the endocrine system: pancreatic beta-cells and the glucose competence concept.
Crosstalk between intracellular signalling systems is recognized as the principal means by which a cell orchestrates coordinate responses to stimulation by neurotransmitters, hormones or growth factors. The functional consequences of crosstalk are evident at multiple levels within a given signalling cascade, including the regulation of receptor-ligand interactions, guanine nucleotide-binding proteins, enzyme activities, ion channel function and gene expression. Here we focus on the pancreatic beta-cells of the islets of Langerhans to illustrate the important role crosstalk plays in the regulation of glucose-induced insulin secretion. Recent studies indicating a synergistic interaction in beta-cells between the glucose-regulated ATP-dependent signalling system and the hormonally regulated cAMP-dependent signalling system are emphasized. This interaction gives beta-cells the ability to match the ambient concentration of glucose to an appropriate insulin secretory response, a process we refer to as the induction of glucose competence. The glucose competence concept may provide new insights into the etiology and treatment of non-insulin-dependent diabetes mellitus (Type II diabetes).
Holz
G G
GG
Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Boston.
Habener
J F
JF
D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D005947:Glucose / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D007328:Insulin; D005947:Glucose