Cited by 86melanin and skin pigmentationMelanoma and MAPK PathwaysAmino Acid Enzymes and Metabolism

The Importance of l-Phenylalanine Transport and Its Autocrine Turnover to l-Tyrosine for Melanogenesis in Human Epidermal Melanocytes

Schallreuter, K.U., Wood, J.M.·1999·Biochemical and Biophysical Research Communications

Abstract

A comparative study of (14)C-labeled l-phenylalanine and (3)H-labeled L-tyrosine uptake in cultures of human melanocytes (n = 8) and keratinocytes (n = 2) identified a significantly more rapid active transport for L-phenylalanine in melanocytes, whereas the slower uptake of L-tyrosine followed a concentration-dependent gradient, confirming facilitated diffusion rather than active transport. In addition, a significantly more efficient autocrine turnover of L-phenylalanine to L-tyrosine via intracellular phenylalanine hydroxylase was demonstrated in melanocytes. The incorporation of the newly synthesized radiolabeled L-tyrosine was directly followed into the end product melanin. The presence of L-phenylalanine in the culture medium produced 40% more melanin compared to an equivalent concentration of L-tyrosine alone. The transport of extracellular L-phenylalanine and its intracellular metabolism to L-tyrosine via intracellular phenylalanine hydroxylase are coupled to calcium uptake/efflux, whereas L-tyrosine uptake is calcium independent. Taken together, our results identified for the first time the importance of autocrine calcium-dependent active l-phenylalanine uptake/turnover in melanocytes as a major pathway for melanogenesis.

Integrity signals

Registry

Crossref · 10.1006/bbrc.1999.1241

Cites

20 of 20 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Schallreuter, K. U., & Wood, J. M.
Affiliations
University of Bradford (GB)
Corresponding author
Schallreuter, K.U.
Venue
Biochemical and Biophysical Research Communications
Publisher
Elsevier BV
Published
1999-08
Volume
262
Issue
2
Pages
423-428
ISSN
0006-291X (ISSN-L)
OpenAlex
W2037745220
Cited by
86
References
20
Citations by year
2026: 2 · 2025: 1 · 2024: 5 · 2023: 3 · 2022: 2 · 2021: 2 · 2020: 2 · 2017: 2 · 2016: 1 · 2015: 4 · 2014: 2 · 2013: 3 · 2012: 2
FWCI
0.82
Type
journal article
Language
en
Open access
closed
Locations
  • Biochemical and Biophysical Research Communications (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › melanin and skin pigmentation
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Melanoma and MAPK Pathways
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biochemistry › Amino Acid Enzymes and Metabolism
Keywords
melanogenesis, human epidermal melanocytes, keratinocytes, phenylalanine hydroxylase, facilitated diffusion, active transport
MeSH terms
Epidermal Cells, Biological Transport, Calcium, Cells, Cultured, Epidermis, Female, Homeostasis, Humans, Male, Melanins, Melanocytes, Phenylalanine, Phenylalanine Hydroxylase, Tyrosine, Autocrine Communication

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review