title: The insulin secretory granule as a signaling hub.
abstract: The insulin granule was previously thought of as merely a container, but accumulating evidence suggests that it also acts as a signaling node. Regulatory pathways intersect at but also originate from the insulin granule membrane. Examples include the small G-proteins Rab3a and Rab27a, which influence granule movement, and the transmembrane proteins (tyrosine phosphatase receptors type N) PTPRN and PTPRN2, which upregulate β-cell transcription and proliferation. In addition, many cosecreted compounds possess regulatory functions, often related to energy metabolism. For instance, ATP and γ-amino butyric acid (GABA) modulate insulin and glucagon secretion, respectively; C-peptide protects β-cells and kidney cells; and amylin reduces gastric emptying and food intake via the brain. In this paper, we review the current knowledge of the insulin granule proteome and discuss its regulatory functions.
authors.affiliation: Molecular Diabetology, Paul Langerhans Institute Dresden, School of Medicine and University Clinic Carl Gustav Carus, Dresden University of Technology, Dresden 01307, Germany.
authors.forename: Jakob
authors.initials: J
authors.lastname: Suckale
authors.forename: Michele
authors.initials: M
authors.lastname: Solimena
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002864:Chromogranins / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism; D022142:Secretory Vesicles / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D002864:Chromogranins; D007328:Insulin; D000255:Adenosine Triphosphate; D020559:Monomeric GTP-Binding Proteins