title: cAMP-binding site of PKA as a molecular target of bisabolangelone against melanocyte-specific hyperpigmented disorder.
abstract: Microphthalmia-associated transcription factor (MITF) is inducible in response to cAMP and has a pivotal role in the melanocyte-specific expression of tyrosinase for skin pigmentation. Here we suggest that the cAMP-binding site of protein kinase A (PKA) is a target in the inhibition of the melanogenic process in melanocytes, as evidenced from the molecular mechanism of small molecules such as bisabolangelone (BISA) and Rp-adenosine 3',5'-cyclic monophosphorothioate (Rp-cAMPS). BISA is a sesquiterpene constituent of Angelica koreana, a plant of the Umbelliferae family, whose roots are used as an alternative medicine. BISA competitively inhibited cAMP binding to the regulatory subunit of PKA and fitted into the cAMP-binding site on the crystal structure of PKA under the most energetically favorable simulation. In α-melanocyte-stimulating hormone (α-MSH)-activated melanocytes, BISA and Rp-cAMPS nullified cAMP-dependent PKA activation, dissociating catalytic subunits from an inactive holoenzyme complex. They resultantly inhibited cellular phosphorylation of the cAMP-responsive element-binding protein (CREB) or another transcription factor SOX9, thus downregulating the expression of MITF or the tyrosinase gene with decreased melanin production. Taken together, this study defined the antimelanogenic mechanism of BISA or Rp-cAMPS with a notable implication of the cAMP-binding site of PKA as a putative target ameliorating melanocyte-specific hyperpigmented disorder.
authors.affiliation: College of Pharmacy & CBITRC, Chungbuk National University, Cheongju, Korea.
authors.forename: Eunmiri
authors.initials: E
authors.lastname: Roh
authors.forename: Cheong-Yong
authors.initials: CY
authors.lastname: Yun
authors.forename: Ji
authors.initials: J
authors.lastname: Young Yun
authors.forename: Dongsun
authors.initials: D
authors.lastname: Park
authors.forename: Nam
authors.initials: N
authors.lastname: Doo Kim
authors.forename: Bang
authors.initials: B
authors.lastname: Yeon Hwang
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Jung
authors.forename: Sun Ki
authors.initials: SK
authors.lastname: Park
authors.forename: Yun-Bae
authors.initials: YB
authors.lastname: Kim
authors.forename: Sang-Bae
authors.initials: SB
authors.lastname: Han
authors.forename: Youngsoo
authors.initials: Y
authors.lastname: Kim
mesh_terms: D029969:Angelica / Q000737:chemistry; D001665:Binding Sites / Q000502:physiology; D050882:CREB-Binding Protein / Q000378:metabolism; D002478:Cells, Cultured; D018360:Crystallography, X-Ray; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D017495:Hyperpigmentation / Q000188:drug therapy* / Q000378:metabolism; D008543:Melanins / Q000096:biosynthesis*; D008544:Melanocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D008517:Phytotherapy / Q000379:methods*; D055758:SOX9 Transcription Factor / Q000378:metabolism; D012717:Sesquiterpenes / Q000494:pharmacology*
chemical_list: C497234:MITF protein, human; D008543:Melanins; D051739:Microphthalmia-Associated Transcription Factor; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human; D012717:Sesquiterpenes; C455067:bisabolangelone; D000242:Cyclic AMP; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; D017868:Cyclic AMP-Dependent Protein Kinases