Cullin-associated NEDD8-dissociated protein 1, a novel interactor of rabphilin-3A, deubiquitylates rabphilin-3A and regulates arginine vasopressin secretion in PC12 cells

Endocrine journal

Seiji Takeuchi¹  Shintaro Iwama¹  Hiroshi Arima¹  Yoshinori Yasuda¹  Naoko Iwata¹  Atsushi Kiyota¹  Kohtaro Nakashima¹  Atsushi Enomoto²  Yoshihisa Sugimura³ 

[1] Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan;Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan;Division of Endocrinology and Metabolism, Department of Internal Medicine, Fujita Health University, Toyoake, Aichi 470-1192 Japan

关键词: Vasopressin;    Rabphilin-3A;    Cullin-associated NEDD8-dissociated protein 1;    Deubiquitylation;    Secretion;   

DOI  :  10.1507/endocrj.EJ17-0399

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

The molecular mechanism involved in the exocytosis of arginine vasopressin (AVP) is not fully known. Rabphilin-3A has been suggested as a novel autoantigen in infundibulo-neurohypophysitis (LINH), which leads to central diabetes insipidus through insufficient secretion of AVP. However, the role of rabphilin-3A in the pathogenesis of LINH remains unclear. Thus, the aim of the present study was to identify proteins binding rabphilin-3A in the posterior pituitary. Using glutathione S-transferase (GST)-pulldown assays and proteomic analyses, cullin-associated NEDD8-dissociated protein 1 (CAND1) was identified as a rabphilin-3A-binding protein in the posterior pituitary. Co-immunoprecipitation assays indicated that CAND1 interacted endogenously with rabphilin-3A. In addition, immunohistochemistry experiments showed that CAND1 immunoreactivity was detected mainly in the posterior pituitary, intermediate lobe, and the supraoptic nucleus in the hypothalamus, and less in the anterior lobe, partially co-localizing with rabphilin-3A. Overexpression of CAND1 resulted in deubiquitylation of rabphilin-3A in PC12 cells. Moreover, overexpression of CAND1 in PC12 cells co-transfected with AVP enhanced both basal and KCl-stimulated AVP secretion. The findings indicate that CAND1 inhibits the ubiquitylation of rabphilin-3A and positively regulates AVP secretion. These data shed light on a novel potential mechanism involving rabphilin-3A in AVP secretion, and suggest a new role of CAND1 as a regulator of hormone or neurotransmitter secretion.

【 授权许可】

Unknown