2013. 8. 3 LEE Byeong Gwon

Abstract

Object : To know melanosome biogenesis step and transport mechanism.

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Abstract Biogenesis Transport Conclusion01Abstract

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Pmel17

an important struc-tural component of melanosomes, is present in the limiting membrane of stage I melanosomes then enters intralu-menal vesicles, un-dergoes proteolytic cleavageand forms the lumenal fibrillar striations that characterise stage II organelles.

Abstract Biogenesis Transport ConclusionBiogenesis02

Melanosomes Are Specialized Members of the Lysosomal Lineage of Organelles, 1995

Abstract Biogenesis Transport ConclusionBiogenesis02

Stage Ⅰ pre-melanosomes are nonpigmented vacuoles that are derived from the endosomal system.

Stage ⅡThese then acquire characteristic internal striations.

Stage ⅢMelanin pigment is deposited onto the striations.

Stage Ⅳeventually giving rise to mature, fully melanised.

Abstract Biogenesis Transport ConclusionTransport03

Abstract Biogenesis Transport ConclusionTransport03

Powering membrane traffic in endocytosis and recycling, 2006

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Different modes of melanin transfer

①Cytophagocytosis ②Phagocytosis ③Membrane fusion ④Vesicular transfer

①

② ③ ④

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Cover picture

The Rab27a GTPase associates with melanosomes and regulates their transport to, and retention in, the pe-ripheral cytoplasm in skin melanocytes. Melanosome transport also requires the microtubule and actin cytoskele-ton. Staining of a cultured murine melanocyte for filamentous actin (red) and microtubules (blue) reveals a close relationship between Rab27a-labelled melanosomes (green) and these cytoskeletal elements.