Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The MLN64 gene, which is localized in q12-q21 of the human chromosome 17, encodes a novel protein containing 2 distinct domains. At the N-terminal, MLN64 exhibits a potential trans-membrane region, while at the C-terminal, it shares homology with the F26F4.4 protein of Coenorhabditis elegans and the steroidogenic acute regulatory (StAR) protein, a mitochondrial protein which is involved in steroid-hormone synthesis. By comparing the C-terminal part of these proteins, we defined a novel protein domain, which we termed SHD for "StAR Homology Domain". Of the 93 primary invasive breast carcinomas that were examined, 14 were found to over-express MLN64. These 14 tumors also expressed high c-erbB-2 transcript levels, which were not detected in the MLN64-negative tumors. MLN64 mRNA and protein were specifically detected in malignant cells of breast carcinomas. MLN64 protein was localized within bundle-like structures distributed throughout the cell cytoplasm and condensed in a perinuclear patch, suggesting an association with a specific cell compartment. When the N-terminal part of MLN64 was deleted, MLN64 was uniformly distributed in the cell cytoplasm, indicating that N-terminal part is involved in the specific cytoplasmic localization of MLN64. The homology between the C-terminal part of MLN64 and the functional StAR domain (SHD) suggests that MLN64 and StAR, although distributed in different cellular compartments, may both play a role in steroidogenesis. In this case, the high levels of MLN64 observed in some breast carcinomas could contribute to the progression of these tumors through increased intratumoral steroidogenesis.
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PMID:MLN64 exhibits homology with the steroidogenic acute regulatory protein (STAR) and is over-expressed in human breast carcinomas. 913 40

MLN64, is invariably coamplified and coexpressed with erbB-2 in breast cancers. The human MLN64 and ERBB2 genes are positioned at less than 50 kb from each other, on chromosome 17q12. To understand the molecular basis of MLN64 overexpression in cancer, the genomic region containing the MLN64 and ERBB2 genes was isolated and mapped. The two genes, DARPP32 and Telethonin, flanking MLN64 respectively on its centromeric and telomeric sides, although coamplified, are not overexpressed in breast cancer cells, indicating that gene amplification is not sufficient to allow overexpression. The MLN64 minimal promoter was isolated and found to be a housekeeping gene promoter containing four potential Sp1 binding elements. Using Sp1-deficient Drosophila SL2 cells, MLN64 promoter activity was induced in a dose-dependent manner by exogenous Sp1 addition. Furthermore, mutation of each individual Sp1 element resulted in a significant decrease in reporter gene activity, indicating that all the Sp1 binding elements are functional and act together to promote gene expression. Since the ERBB2 promoter is also positively regulated by Sp1, this study indicates that MLN64 and ERBB2 genes share common transcriptional controls together with a physical link on chromosome 17q. We speculate that, in addition to the oncogenic potential of erbB-2 overexpression, the unbalanced action of MLN64 contributes to the poor clinical outcome of breast tumors bearing this amplified region.
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PMID:Metastatic lymph node 64 (MLN64), a gene overexpressed in breast cancers, is regulated by Sp/KLF transcription factors. 1280 84