Schraermeyer U
Institut für Biologie II (Zoologie), RWTH Aachen, Germany.
Pigment Cell Res. 1995 Aug;8(4):209-14. doi: 10.1111/j.1600-0749.1995.tb00665.x.
Cultured choroidal melanocytes from cattle where incubated with gold labeled albumin. After phagocytosis of the labeled protein, the label appeared inside the melanin granules, as was observed under the electron microscope. Melanin granules associated with gold particles were also exocytosed into the culture medium by the melanocytes. The results of this study show that endosomes or phagosomes are transported from the cell surface of a melanocyte to the melanin granule. Therefore, melanin granules are part of the lysosomal degradation pathway. The possibility that albumin is degraded by proteases present in lysosomes and melanosomes and that the tyrosine released during degradation is used as a substrate by tyrosinase and thereby converted to melanin is discussed. The present study additionally shows that the choroidea of cattle can be used as a source for cell culture of melanocytes.
将牛的脉络膜黑素细胞进行培养，并与金标记的白蛋白一起孵育。在吞噬标记蛋白后，在电子显微镜下观察到标记物出现在黑素颗粒内部。与金颗粒相关的黑素颗粒也被黑素细胞胞吐到培养基中。本研究结果表明，内体或吞噬体从黑素细胞的细胞表面转运至黑素颗粒。因此，黑素颗粒是溶酶体降解途径的一部分。文中讨论了白蛋白被溶酶体和黑素小体中存在的蛋白酶降解，以及降解过程中释放的酪氨酸被酪氨酸酶用作底物并由此转化为黑色素的可能性。本研究还表明，牛的脉络膜可作为黑素细胞培养的细胞来源。
