Biomedical subjects

Elaine Fuchs

Publications and source records attributed to Elaine Fuchs.

58 records · Page 4Linked to original sources

PubMed2002

Getting under the skin of epidermal morphogenesis.

At the surface of the skin, the epidermis serves as the armour for the body. Scientists are now closer than ever to understanding how the epidermis accomplishes this extraordinary feat, and is able to survive and replenish itself under the harshest conditions that face any tissue. By combining genetic engineering with cell-biological studies and with human genome data analyses, skin biologists are discovering the mechanisms that underlie the development and differentiation of the epidermis and hair follicles of the skin. This explosion of knowledge paves the way for new discoveries into the genetic bases of human skin disorders and for developing new therapeutics.

Animals↗

PubMed2002

Dissection of a complex enhancer element: maintenance of keratinocyte specificity but loss of differentiation specificity.

In this report, we explored the mechanisms underlying keratinocyte-specific and differentiation-specific gene expression in the skin. We have identified five keratinocyte-specific, open chromatin regions that exist within the 6 kb of 5' upstream regulatory sequence known to faithfully recapitulate the strong endogenous keratin 5 (K5) promoter and/or enhancer activity. One of these, DNase I-hypersensitive site (HSs) 4, was unique in that it acted independently to drive abundant and keratinocyte-specific reporter gene activity in culture and in transgenic mice, despite the fact that it was not essential for K5 enhancer activity. We have identified evolutionarily conserved regulatory elements and a number of their associated proteins that bind to this compact and complex enhancer element. The 125-bp 3' half of this element (referred to as 4.2) is by far the smallest known strong enhancer element possessing keratinocyte-specific activity in vivo. Interestingly, its activity is restricted to a subset of progeny of K5-expressing cells located within the sebaceous gland. The other half of HSs 4 (termed 4.1) possesses activity to suppress sebocyte-specific expression and induce expression in the channel (inner root sheath) cells surrounding the hair shaft. Our findings lead us to a view of keratinocyte gene expression which is determined by multiple regulatory modules, many of which contain AP-2 and/or Sp1/Sp3 binding sites for enhancing expression in skin epithelium, but which also harbor one or more unique sites for the binding of factors which determine specificity. Through mixing and matching of these modules, additional levels of specificity are obtained, indicating that both transcriptional repressors and activators govern the specificity.

Animals↗

PubMed2002

Structure and transcription of the human m3 muscarinic receptor gene.

We have isolated and characterized the human m3 muscarinic receptor gene and its promoter. Using 5' rapid amplification of cDNA ends (RACE), internal polymerase chain reaction (PCR), and homology searching to identify EST clones, we determined that the cDNA encoding the m3 receptor comprises 4,559 bp in 8 exons, which are alternatively spliced to exclude exons 2, 4, 6, and/or 7; the receptor coding sequence occurs within exon 8. Analysis of P1 artificial chromosome (PAC) and bacterial artificial chromosome (BAC) clones and of PCR- amplified genomic DNA, and homology searching of human chromosome 1 sequence provided from the Sanger Centre (Hinxton, Cambridge, UK) revealed that the m3 muscarinic receptor gene spans at least 285 kb. A promoter fragment containing bp -1240 to +101 (relative to the most 5' transcription start site) exhibited considerable transcriptional activity during transient transfection in cultured subconfluent, serum-fed canine tracheal myocytes, and 5' deletion analysis of promoter function revealed the presence of positive transcriptional regulatory elements between bp -526 and -269. Sequence analysis disclosed three potential AP-2 binding sites in this region; five more AP-2 consensus binding motifs occur between bp -269 and +101. Cotransfection with a plasmid expressing human AP-2alpha substantially increased transcription from m3 receptor promoter constructs containing 526 or 269 bp of 5' flanking DNA. Furthermore, m3 receptor promoter activity was enhanced by long-term serum deprivation of canine tracheal myocytes, a treatment that is known to increase AP-2 transcription-promoting activity in these cells. Together, these data suggest that expression of the human m3 muscarinic receptor gene is regulated in part by AP-2 in airway smooth muscle.

Alternative Splicing↗

PubMed2002

Defining the mandate of proteomics in the post-genomics era: workshop report.

Research in proteomics is the next step after genomics in understanding life processes at the molecular level. In the largest sense proteomics encompasses knowledge of the structure, function and expression of all proteins in the biochemical or biological contexts of all organisms. Since that is an impossible goal to achieve, at least in our lifetimes, it is appropriate to set more realistic, achievable goals for the field. Up to now, primarily for reasons of feasibility, scientists have tended to concentrate on accumulating information about the nature of proteins and their absolute and relative levels of expression in cells (the primary tools for this have been 2D gel electrophoresis and mass spectrometry). Although these data have been useful and will continue to be so, the information inherent in the broader definition of proteomics must also be obtained if the true promise of the growing field is to be realized. Acquiring this knowledge is the challenge for researchers in proteomics and the means to support these endeavors need to be provided. An attempt has been made to present the major issues confronting the field of proteomics and two clear messages come through in this report. The first is that the mandate of proteomics is and should be much broader than is frequently recognized. The second is that proteomics is much more complicated than sequencing genomes. This will require new technologies but it is highly likely that many of these will be developed. Looking back 10 to 20 years from now, the question is: Will we have done the job wisely or wastefully? This report summarizes the presentations made at a symposium at the National Academy of Sciences on February 25, 2002.

Computational Biology↗