TY - JOUR
T1 - Rab32/38-Dependent and -Independent Transport of Tyrosinase to Melanosomes in B16-F1 Melanoma Cells
AU - Nishizawa, Aya
AU - Maruta, Yuto
AU - Fukuda, Mitsunori
N1 - Funding Information:
This work was supported in part by Grant-in-Aid for Scientific Research (B) 22H02613 from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan (to M.F.), Japan Science Technology Agency (JST) CREST Grant JPMJCR17H4 (to M.F.), and JST, the establishment of university fellowships towards the creation of science technology innovation, Grant JPMJFS2102 (to Y.M.).
Publisher Copyright:
© 2022 by the authors.
PY - 2022/11
Y1 - 2022/11
N2 - B16-F1 melanoma cells have often been used as a model to investigate melanogenesis, but the evidence that melanosome biogenesis and transport occur by the same mechanisms in normal melanocytes and B16-F1 cells is insufficient. In this study, we established knockout B16-F1 cells for each of several key factors in melanogenesis, i.e., tyrosinase (Tyr), Hps4, Rab27A, and Rab32·Rab38 (Rab32/38), and then compared their phenotypes with the phenotypes of corresponding mutant mouse melanocyte cell lines, i.e., melan-c, melan-le, melan-ash, and Rab32-deficient melan-cht cells, respectively. The results showed that Tyr and Rab27A are also indispensable for melanin synthesis and peripheral melanosome distribution, respectively, in B16-F1 cells, but that Hps4 or its downstream targets Rab32/38 are not essential for Tyr transport in B16-F1 cells, suggesting the existence of a Rab32/38-independent Tyr transport mechanism in B16-F1 cells. We then performed comprehensive knockdown screening of Rab small GTPases and identified Rab10 and Rab24, previously uncharacterized Rabs in melanocytes, as being involved in Tyr transport under Rab32/38-null conditions. Our findings indicate a difference between the Tyr transport mechanism in melanocytes and B16-F1 cells in terms of Rab32/38-dependency and a limitation in regard to using melanoma cells as a model for melanocytes, especially when investigating the mechanism of endosomal Tyr transport.
AB - B16-F1 melanoma cells have often been used as a model to investigate melanogenesis, but the evidence that melanosome biogenesis and transport occur by the same mechanisms in normal melanocytes and B16-F1 cells is insufficient. In this study, we established knockout B16-F1 cells for each of several key factors in melanogenesis, i.e., tyrosinase (Tyr), Hps4, Rab27A, and Rab32·Rab38 (Rab32/38), and then compared their phenotypes with the phenotypes of corresponding mutant mouse melanocyte cell lines, i.e., melan-c, melan-le, melan-ash, and Rab32-deficient melan-cht cells, respectively. The results showed that Tyr and Rab27A are also indispensable for melanin synthesis and peripheral melanosome distribution, respectively, in B16-F1 cells, but that Hps4 or its downstream targets Rab32/38 are not essential for Tyr transport in B16-F1 cells, suggesting the existence of a Rab32/38-independent Tyr transport mechanism in B16-F1 cells. We then performed comprehensive knockdown screening of Rab small GTPases and identified Rab10 and Rab24, previously uncharacterized Rabs in melanocytes, as being involved in Tyr transport under Rab32/38-null conditions. Our findings indicate a difference between the Tyr transport mechanism in melanocytes and B16-F1 cells in terms of Rab32/38-dependency and a limitation in regard to using melanoma cells as a model for melanocytes, especially when investigating the mechanism of endosomal Tyr transport.
KW - Hps4
KW - Rab small GTPase
KW - endosome
KW - melanocyte
KW - melanogenic enzyme
KW - melanoma
KW - melanosome
KW - membrane traffic
KW - tyrosinase
KW - tyrosinase-related protein 1 (Tyrp1)
UR - http://www.scopus.com/inward/record.url?scp=85142835160&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85142835160&partnerID=8YFLogxK
U2 - 10.3390/ijms232214144
DO - 10.3390/ijms232214144
M3 - Article
C2 - 36430618
AN - SCOPUS:85142835160
SN - 1422-0067
VL - 23
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 22
M1 - 14144
ER -