Tyrosinase biosynthesis in adult mammalian retinal pigment epithelial cells

Ulrich Schraermeyer; Jürgen Kopitz; Swaantje Peters; Sigrid Henke-Fahle; Petra Blitgen-Heinecke; Despina Kokkinou; Tobias Schwarz; Karl-Ulrich Bartz-Schmidt

doi:10.1016/j.exer.2005.12.015

Tyrosinase biosynthesis in adult mammalian retinal pigment epithelial cells

Ulrich Schraermeyer, Jürgen Kopitz, Swaantje Peters, Sigrid Henke-Fahle, Petra Blitgen-Heinecke, Despina Kokkinou, Tobias Schwarz, Karl-Ulrich Bartz-Schmidt

University of Tubingen

Abstract

Tyrosinase (EC 1.14.18.1) is the rate limiting enzyme of melanogenesis and it is unclear whether it is synthesized in postnatal retinal pigment epithelium (RPE). Cultured RPE cells from cattle were fed with isolated rod outer segments (ROS). After phagocytosis, RPE cells were tested for tyrosinase presence and activity with three independent methods: (1) ultrastructural DOPA (l-3,4-dihydroxyphenylalanine) histochemistry (2) immunocytochemistry with anti-tyrosinase antibodies (3) measuring tyrosine hydroxylase activity using [(3)H]tyrosine. With all three methods tyrosinase was found in RPE cells after ROS-feeding but was absent without feeding. In contrast to the classical hypothesis, we demonstrated with three independent methods that the expression of tyrosinase and its enzymatic activity are induced in cultured adult RPE by phagocytosis of rod outer segments (ROS) in vitro.

Original language	English
Journal	Experimental Eye Research
Volume	83
Issue number	2
Pages (from-to)	315-21
Number of pages	7
ISSN	0014-4835
DOIs	https://doi.org/10.1016/j.exer.2005.12.015
Publication status	Published - 08.2006
Externally published	Yes

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title = "Tyrosinase biosynthesis in adult mammalian retinal pigment epithelial cells",

abstract = "Tyrosinase (EC 1.14.18.1) is the rate limiting enzyme of melanogenesis and it is unclear whether it is synthesized in postnatal retinal pigment epithelium (RPE). Cultured RPE cells from cattle were fed with isolated rod outer segments (ROS). After phagocytosis, RPE cells were tested for tyrosinase presence and activity with three independent methods: (1) ultrastructural DOPA (l-3,4-dihydroxyphenylalanine) histochemistry (2) immunocytochemistry with anti-tyrosinase antibodies (3) measuring tyrosine hydroxylase activity using [(3)H]tyrosine. With all three methods tyrosinase was found in RPE cells after ROS-feeding but was absent without feeding. In contrast to the classical hypothesis, we demonstrated with three independent methods that the expression of tyrosinase and its enzymatic activity are induced in cultured adult RPE by phagocytosis of rod outer segments (ROS) in vitro.",

author = "Ulrich Schraermeyer and J{\"u}rgen Kopitz and Swaantje Peters and Sigrid Henke-Fahle and Petra Blitgen-Heinecke and Despina Kokkinou and Tobias Schwarz and Karl-Ulrich Bartz-Schmidt",

year = "2006",

month = aug,

doi = "10.1016/j.exer.2005.12.015",

language = "English",

volume = "83",

pages = "315--21",

journal = "Experimental Eye Research",

issn = "0014-4835",

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TY - JOUR

T1 - Tyrosinase biosynthesis in adult mammalian retinal pigment epithelial cells

AU - Schraermeyer, Ulrich

AU - Kopitz, Jürgen

AU - Peters, Swaantje

AU - Henke-Fahle, Sigrid

AU - Blitgen-Heinecke, Petra

AU - Kokkinou, Despina

AU - Schwarz, Tobias

AU - Bartz-Schmidt, Karl-Ulrich

PY - 2006/8

Y1 - 2006/8

N2 - Tyrosinase (EC 1.14.18.1) is the rate limiting enzyme of melanogenesis and it is unclear whether it is synthesized in postnatal retinal pigment epithelium (RPE). Cultured RPE cells from cattle were fed with isolated rod outer segments (ROS). After phagocytosis, RPE cells were tested for tyrosinase presence and activity with three independent methods: (1) ultrastructural DOPA (l-3,4-dihydroxyphenylalanine) histochemistry (2) immunocytochemistry with anti-tyrosinase antibodies (3) measuring tyrosine hydroxylase activity using [(3)H]tyrosine. With all three methods tyrosinase was found in RPE cells after ROS-feeding but was absent without feeding. In contrast to the classical hypothesis, we demonstrated with three independent methods that the expression of tyrosinase and its enzymatic activity are induced in cultured adult RPE by phagocytosis of rod outer segments (ROS) in vitro.

AB - Tyrosinase (EC 1.14.18.1) is the rate limiting enzyme of melanogenesis and it is unclear whether it is synthesized in postnatal retinal pigment epithelium (RPE). Cultured RPE cells from cattle were fed with isolated rod outer segments (ROS). After phagocytosis, RPE cells were tested for tyrosinase presence and activity with three independent methods: (1) ultrastructural DOPA (l-3,4-dihydroxyphenylalanine) histochemistry (2) immunocytochemistry with anti-tyrosinase antibodies (3) measuring tyrosine hydroxylase activity using [(3)H]tyrosine. With all three methods tyrosinase was found in RPE cells after ROS-feeding but was absent without feeding. In contrast to the classical hypothesis, we demonstrated with three independent methods that the expression of tyrosinase and its enzymatic activity are induced in cultured adult RPE by phagocytosis of rod outer segments (ROS) in vitro.

U2 - 10.1016/j.exer.2005.12.015

DO - 10.1016/j.exer.2005.12.015

M3 - Journal articles

C2 - 16579986

SN - 0014-4835

VL - 83

SP - 315

EP - 321

JO - Experimental Eye Research

JF - Experimental Eye Research

IS - 2

ER -

Tyrosinase biosynthesis in adult mammalian retinal pigment epithelial cells

Abstract

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