Under physiological conditions, calcium (Ca2+) regulates essential functions of polarized secretory cells by the stimulation of specific Ca2+ signaling mechanisms, such as increases in intracellular Ca2+ concentration ([Ca2+]i) via the store-operated Ca2+ entry (SOCE) and the receptor-operated Ca2+ entry (ROCE). Homer proteins are scaffold proteins that interact with G protein-coupled receptors, inositol 1,4,5-triphosphate (IP3) receptors, Orai1-stromal interaction molecule 1, and transient receptor potential canonical (TRPC) channels. However, their role in the Ca2+ signaling in exocrine cells remains unknown. In this study, we investigated the role of Homer2 in the Ca2+ signaling and regulatory channels to mediate SOCE and ROCE in pancreatic acinar cells. Deletion of Homer2 (Homer2–/–) markedly increased the expression of TRPC3, TRPC6, and Orai1 in pancreatic acinar cells, whereas these expressions showed no difference in whole brains of wild-type and Homer2–/– mice. Furthermore, the response of Ca2+ entry by carbachol also showed significant changes to the patterns regulated by specific blockers of SOCE and ROCE in pancreatic acinar cells of Homer2–/– mice. Thus, these results suggest that Homer2 plays a critical role in the regulatory action of the [Ca2+]i via SOCE and ROCE in mouse pancreatic acinar cells.

Introduction
Materials and Methods
    1. 재료
    2. 실험동물
    3. 췌장의 선세포 분리
    4. 중합효소 연쇄 반응(polymerase chain reaction, PCR)분석
    5. [Ca2+]i 측정
    6. 실험자료의 통계 분석
Results
    1. 칼슘 유입을 매개하는 채널들의 발현 양상
    2. 특정 억제제에 의한 수용체-의존성 칼슘 유입의 조절 변화
Discussion
References

• Jung Yun Kang(Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry/Department of Dental Hygiene, College of Software Digital Healthcare Convergence, Yonsei University)
• Namju Kang(Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry)
• Yu-Mi Yang(Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry) Correspondence to