Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The genes for orosomucoid (ORM-1 and ORM-2), delta-aminolevulinate dehydratase (ALAD), and hexabrachion or tenascin (HXB) all map to the q31-qter region of human Chromosome (Chr) 9. The mouse homolog of each of these genes has been mapped to Chr4, but hexabrachion has not previously been mapped by linkage analysis. We have now ordered Orm-1, Lv (the mouse homolog of ALAD), and Hxb in an interspecific backcross panel, by use of tyrosinase related protein-1, Tyrp-1, whose human homolog maps to 9p13-pter (Abbott et al., Genomics 1991) as a reference locus. No recombinants were identified in 124 animals between Lv and Orm-1. Hxb was found to be 1.6 cM distal to Lv and Orm-1, and 4.8 cM proximal to Tyrp-1, or b. These data therefore contribute to our knowledge of the conserved synteny between HSA 9q and MMU 4.
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PMID:Comparative mapping of mouse chromosome 4 and human chromosome 9: Lv, Orm, and Hxb are closely linked on mouse chromosome 4. 137 92

To gain insight into the role of Oa1, the mouse homolog of the human X-linked ocular albinism 1 protein, its properties and subcellular localization were investigated. Antiserum raised against an expressed segment of the Oa1 protein recognized a band of approximately 48 kDa in immunoblots of extracts of cultured mouse melan-a melanocytes, but not of cells of non-melanocyte origin. When melanocyte extracts were treated with glycopeptidase F, a approximately 44 kDa band appeared. Like the melanogenic enzyme tyrosinase, expression of Oa1 was stimulated by alpha-melanocyte stimulating hormone and inhibited by agouti signal protein. Upon density gradient centrifugation of organelles of melan-a cells, Oa1 protein colocalized with the late endosomal/lysosomal marker Lamp1, but only partial overlap was observed with melanosomal proteins in the high density region of the gradient. Immunofluorescence staining revealed that neither endogenous Oa1 nor an Oa1-green fluorescent protein fusion product colocalized with the melanosomal protein tyrosinase related protein-1 in the cell periphery. In contrast, colocalization of Oa1 and Oa1-green fluorescent protein fusion product with Lamp1 was extensive throughout the cell. These results indicate that Oa1 is a melanocyte-specific integral membrane glycoprotein localized to late endosomes/lysosomes but not mature melanosomes. Considering the microscopic findings in patients with X-linked ocular albinism 1, we speculate that Oa1 may play a role in the trafficking of vesicles to developing melanosomes.
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PMID:The mouse ocular albinism 1 gene product is an endolysosomal protein. 1118 Sep 81

The Dark brown (DB) mutation in chickens reduces expression of black eumelanin and enhances expression of red pheomelanin, but only in certain parts of the plumage. Here, we present genetic evidence that an 8.3-kb deletion upstream of the SOX10 transcription start site is the causal mutation underlying the DB phenotype. The SOX10 transcription factor has a well-established role in melanocyte biology and is essential for melanocyte migration and survival. Previous studies have demonstrated that the mouse homolog of a highly conserved element within the deleted region is a SOX10 enhancer. The mechanism of action of this mutation remains to be established, but one possible scenario is that the deletion leads to reduced SOX10 expression which in turn down-regulates expression of key enzymes in pigment synthesis such as tyrosinase. Lower tyrosinase activity leads to a shift toward a more pheomelanistic (reddish) plumage color, which is the characteristic feature of the DB phenotype.
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PMID:The Dark brown plumage color in chickens is caused by an 8.3-kb deletion upstream of SOX10. 2121 Sep 60