Disease relevance of Rab8a

• DNA isolated from cell line Mel Swift, a human melanoma cell line, transforms NIH3T3 cells [1].
• Taken together, it is suggestive that Rab8, in B16 melanoma cells, might have a role in melanosome traffic and dendrite extension, both in constitutive and regulated fashion [2].
• P44 Ro (Mel) is a human malignant melanoma cell line derived from a testicular metastasis in a DNA repair deficient, xeroderma pigmentosum patient [3].

High impact information on Rab8a

• This translocation is dependent on the GTPase activity of Rab8, an interactor of optineurin [4].
• Previously, we showed that the N-terminal Slp homology domain of Slp4-a interacts with the GTP-bound form of Rab3A, Rab8, and Rab27A both in vitro and in intact cells (Kuroda, T. S., Fukuda, M., Ariga, H., and Mikoshiba, K. (2002) J. Biol. Chem. 277, 9212-9218) [5].
• Linkage and genetic distance were established for 10 loci by analysis of 114 meiotic events and indicated the following gene order: (centromere)-Insr-3.5 cM-Plat-26.3 cM-Crryps/Mel/Jund-3.5 cM-Junb/Ucp-10.5 cM-Mt-1-27.2 cM-Acta2-0.9 cM-Aprt [6].
• Further, suppression of Rab8 expression by its antisense oligonucleotide revealed the reduction in staining intensity of Rab8 but not of Mel5, dendrite formation and melanosome transport towards the tips of the dendrites in B16 melanoma cells [2].
• Since process formation is supported by cytoskeletal assembly as well as membrane transport, we tested the colocalization of Rab8 with actin filaments in B16 cells [2].

Biological context of Rab8a

• Optineurin increases cell survival and translocates to the nucleus in a Rab8-dependent manner upon an apoptotic stimulus [4].
• The viability of the parent K-12 strain in the cecal content of mice is significantly higher than that of its Mel- mutant phenotype [7].

Anatomical context of Rab8a

• Confocal immunofluorescence microscopic studies revealed that Rab8 is colocalized with Mel5, a melanosomal protein, at the trans-Golgi area and in the cytoplasmic vesicles of B16 cells [2].

Associations of Rab8a with chemical compounds

• Here, we present evidence that Rab8, a member of the small GTPase superfamily, is present in purified melanosomal fractions, and is upregulated by pigmentogenic agents like melanocyte-stimulating hormone/isobutylmethyl xanthine (MSH/IBMX) and ultraviolet radiation B (UVB) [2].

References