TY - JOUR
T1 - Phospholipase C-related catalytically inactive protein (PRIP) controls KIF5B-mediated insulin secretion
AU - Asano, Satoshi
AU - Nemoto, Tomomi
AU - Kitayama, Tomoya
AU - Harada, Kae
AU - Zhang, Jun
AU - Harada, Kana
AU - Tanida, Isei
AU - Hirata, Masato
AU - Kanematsu, Takashi
N1 - Funding Information:
This work was supported by the Funding Program for Next Generation World-Leading Researchers [LS087 to T. Kanematsu], and by grants from JSPS KAKENHI [grant numbers 24229009 to M.H., 25861756 to S.A.].
Funding Information:
We thank Ms Atsuko Shintani and Ms Tamaki Kise at the National Institute for Physiological Sciences and Dr Hiroyuki Hatakeyama at Tohoku University for technical assistance. This work was performed at the Analysis Center of Life Science, Natural Science Center for Basic Research and Development, Hiroshima University
PY - 2014/6/15
Y1 - 2014/6/15
N2 - We previously reported that phospholipase C-related catalytically inactive protein (PRIP)-knockout mice exhibited hyperinsulinemia. Here, we investigated the role of PRIP in insulin granule exocytosis using Prip-knockdown mouse insulinoma (MIN6) cells. Insulin release from Prip-knockdown MIN6 cells was higher than that from control cells, and Prip knockdown facilitated movement of GFP-phogrinlabeled insulin secretory vesicles. Double-immunofluorescent staining and density step-gradient analyses showed that the KIF5B motor protein co-localized with insulin vesicles in Prip-knockdown MIN6 cells. Knockdown of GABAA -receptor-associated protein (GABARAP), a microtubule-associated PRIP-binding partner, by Gabarap silencing in MIN6 cells reduced the co-localization of insulin vesicles with KIF5B and the movement of vesicles, resulting in decreased insulin secretion. However, the co-localization of KIF5B with microtubules was not altered in Prip- and Gabarap-knockdown cells. The presence of unbound GABARAP, freed either by an interference peptide or by Prip silencing, in MIN6 cells enhanced the co-localization of insulin vesicles with microtubules and promoted vesicle mobility. Taken together, these data demonstrate that PRIP and GABARAP function in a complex to regulate KIF5B-mediated insulin secretion, providing new insights into insulin exocytic mechanisms.
AB - We previously reported that phospholipase C-related catalytically inactive protein (PRIP)-knockout mice exhibited hyperinsulinemia. Here, we investigated the role of PRIP in insulin granule exocytosis using Prip-knockdown mouse insulinoma (MIN6) cells. Insulin release from Prip-knockdown MIN6 cells was higher than that from control cells, and Prip knockdown facilitated movement of GFP-phogrinlabeled insulin secretory vesicles. Double-immunofluorescent staining and density step-gradient analyses showed that the KIF5B motor protein co-localized with insulin vesicles in Prip-knockdown MIN6 cells. Knockdown of GABAA -receptor-associated protein (GABARAP), a microtubule-associated PRIP-binding partner, by Gabarap silencing in MIN6 cells reduced the co-localization of insulin vesicles with KIF5B and the movement of vesicles, resulting in decreased insulin secretion. However, the co-localization of KIF5B with microtubules was not altered in Prip- and Gabarap-knockdown cells. The presence of unbound GABARAP, freed either by an interference peptide or by Prip silencing, in MIN6 cells enhanced the co-localization of insulin vesicles with microtubules and promoted vesicle mobility. Taken together, these data demonstrate that PRIP and GABARAP function in a complex to regulate KIF5B-mediated insulin secretion, providing new insights into insulin exocytic mechanisms.
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U2 - 10.1242/bio.20147591
DO - 10.1242/bio.20147591
M3 - Article
AN - SCOPUS:84979036957
VL - 3
SP - 463
EP - 474
JO - Biology Open
JF - Biology Open
SN - 2046-6390
IS - 6
ER -