title: Keratinocyte-derived laminin-332 protein promotes melanin synthesis via regulation of tyrosine uptake.
abstract: Melanocytes, which produce the pigment melanin, are known to be closely regulated by neighboring keratinocytes. However, how keratinocytes regulate melanin production is unclear. Here we report that melanin production in melanoma cells (B16F10 and MNT-1) was increased markedly on a keratinocyte-derived extracellular matrix compared with a melanoma cell-derived extracellular matrix. siRNA-mediated reduction of keratinocyte-derived laminin-332 expression decreased melanin synthesis in melanoma cells, and laminin-332, but not fibronectin, enhanced melanin content and α-melanocyte-stimulating hormone-regulated melanin production in melanoma cells. Similar effects were observed in human melanocytes. Interestingly, however, laminin-332 did not affect the expression or activity of tyrosinase. Instead, laminin-332 promoted the uptake of extracellular tyrosine and, subsequently, increased intracellular levels of tyrosine in both melanocytes and melanoma cells. Taken together, these data strongly suggest that keratinocyte-derived laminin-332 contributes to melanin production by regulating tyrosine uptake.
authors.affiliation: From the Department of Life Sciences, Research Center for Cellular Homeostasis and.
authors.forename: Heesung
authors.initials: H
authors.lastname: Chung
authors.affiliation: From the Department of Life Sciences, Research Center for Cellular Homeostasis and.
authors.forename: Hyejung
authors.initials: H
authors.lastname: Jung
authors.affiliation: From the Department of Life Sciences, Research Center for Cellular Homeostasis and.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Life Sciences, Interdisciplinary Program of EcoCreative, Ewha Womans University, Seoul 120-750, Korea and.
authors.forename: Hye Yun
authors.initials: HY
authors.lastname: Oh
authors.affiliation: Department of Life Sciences, Interdisciplinary Program of EcoCreative, Ewha Womans University, Seoul 120-750, Korea and.
authors.forename: Ok Bin
authors.initials: OB
authors.lastname: Kim
authors.affiliation: the College of Medicine, Department of Physiology and Biophysics, Inha University, Incheon 402-751, Korea.
authors.forename: Inn-Oc
authors.initials: IO
authors.lastname: Han
authors.affiliation: From the Department of Life Sciences, Research Center for Cellular Homeostasis and OhES@ewha.ac.kr.
authors.forename: Eok-Soo
authors.initials: ES
authors.lastname: Oh
mesh_terms: D000818:Animals; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D008543:Melanins / Q000096:biosynthesis*; D008546:Melanoma, Experimental / Q000378:metabolism / Q000473:pathology; D051379:Mice; D034741:RNA, Small Interfering / Q000235:genetics; D014443:Tyrosine / Q000378:metabolism*; D000521:alpha-MSH / Q000378:metabolism; D000097794:Kalinin
chemical_list: D015815:Cell Adhesion Molecules; D008543:Melanins; D034741:RNA, Small Interfering; D014443:Tyrosine; D000521:alpha-MSH; D000097794:Kalinin
keywords: Extracellular Matrix Protein; Keratinocyte; Laminin; Melanocytes; Melanogenesis; Melanoma; l-tyrosine