Recognizes as substrates free retinal and cellular retinol-binding protein-bound retinal. Seems to be the key enzyme in the formation of an RA gradient along the dorso-ventral axis during the early eye development and also in the development of the olfactory system (By similarity).
Retinoic acid (RA) is the form of vitamin A that controls differentiation and proliferation of epithelia. Our previous work established that normal breast epithelia synthesize RA from retinol, an ability retained by three immortalized but nontumorigenic cell lines but lost in five of six breast cell lines. In this work, we characterize the cause of this defect in one of the lines, the MCF-7 line. We have determined that the immortalized but nontumorigenic cell line, MTSV1.7, capable of synthesizing RA from both retinol and retinal, contains a retinaldehyde dehydrogenase activity for the second step in RA biosynthesis. We have identified it, after isolation, as a previously described enzyme, aldehyde dehydrogenase 6 (ALDH6). Immunohistochemical analysis of normal human breast with antibodies to ALDH6 showed expression of this enzyme in the glandular epithelia colocalized with cellular RA-binding protein type II, a possible marker for certain cells able to synthesize RA. ALDH6 was not present in MCF-7 cells, and these cells were unable to oxidize retinal to RA in culture. When MCF-7 cells were then transfected with ALDH6, they (re)gained the ability to oxidize retinal to RA as well as some ability to synthesize RA when provided with retinol. This suggests that loss of ALDH6 expression is the defect in RA biosynthesis in these cells. Identification of ALDH6 as the retinaldehyde dehydrogenase present in normal human breast epithelia provides the first tool necessary for studying the loss of RA synthetic ability in cancer cells and the relationship of this process to malignant transformation.
Interacting selectively and non-covalently with the oxidized form, NAD, of nicotinamide adenine dinucleotide, a coenzyme involved in many redox and biosynthetic reactions.
Retinoic acid (RA) is the form of vitamin A that controls differentiation and proliferation of epithelia. Our previous work established that normal breast epithelia synthesize RA from retinol, an ability retained by three immortalized but nontumorigenic cell lines but lost in five of six breast cell lines. In this work, we characterize the cause of this defect in one of the lines, the MCF-7 line. We have determined that the immortalized but nontumorigenic cell line, MTSV1.7, capable of synthesizing RA from both retinol and retinal, contains a retinaldehyde dehydrogenase activity for the second step in RA biosynthesis. We have identified it, after isolation, as a previously described enzyme, aldehyde dehydrogenase 6 (ALDH6). Immunohistochemical analysis of normal human breast with antibodies to ALDH6 showed expression of this enzyme in the glandular epithelia colocalized with cellular RA-binding protein type II, a possible marker for certain cells able to synthesize RA. ALDH6 was not present in MCF-7 cells, and these cells were unable to oxidize retinal to RA in culture. When MCF-7 cells were then transfected with ALDH6, they (re)gained the ability to oxidize retinal to RA as well as some ability to synthesize RA when provided with retinol. This suggests that loss of ALDH6 expression is the defect in RA biosynthesis in these cells. Identification of ALDH6 as the retinaldehyde dehydrogenase present in normal human breast epithelia provides the first tool necessary for studying the loss of RA synthetic ability in cancer cells and the relationship of this process to malignant transformation.
The biological process whose specific outcome is the progression of a face from an initial condition to its mature state. The face is the ventral division of the head.
The progression of the nucleus accumbens over time from its initial formation until its mature state. The nucleus accumbens is a collection of pleomorphic cells in the caudal part of the anterior horn of the lateral ventricle, in the region of the olfactory tubercle, lying between the head of the caudate nucleus and the anterior perforated substance. It is part of the ventral striatum, a composite structure considered part of the basal ganglia.
The biological process whose specific outcome is the progression of the olfactory pit from an initial condition to its mature state. This process begins with the formation of the olfactory pit, which is an indentation of the olfactory placode, and ends when the pits hollows out to form the nasopharynx.
IEAOrtholog Compara
Optic cup morphogenesis involved in camera-type eye developmentdefinition[GO:0002072]‹silver
The invagination of the optic vesicle to form two-walled indentations, the optic cups, that will go on to form the retina. This process begins with the optic vesicle becoming a two-walled structure and its subsequent shape changes. It does not include the fate commitment of cells to become the pigmented retina and the neural retina. An example of this process is found in Mus musculus.
The chemical reactions and pathways involving retinal, a compound that plays an important role in the visual process in most vertebrates. In the retina, retinal combines with opsins to form visual pigments. Retinal is one of the forms of vitamin A.
Retinoic acid (RA) is the form of vitamin A that controls differentiation and proliferation of epithelia. Our previous work established that normal breast epithelia synthesize RA from retinol, an ability retained by three immortalized but nontumorigenic cell lines but lost in five of six breast cell lines. In this work, we characterize the cause of this defect in one of the lines, the MCF-7 line. We have determined that the immortalized but nontumorigenic cell line, MTSV1.7, capable of synthesizing RA from both retinol and retinal, contains a retinaldehyde dehydrogenase activity for the second step in RA biosynthesis. We have identified it, after isolation, as a previously described enzyme, aldehyde dehydrogenase 6 (ALDH6). Immunohistochemical analysis of normal human breast with antibodies to ALDH6 showed expression of this enzyme in the glandular epithelia colocalized with cellular RA-binding protein type II, a possible marker for certain cells able to synthesize RA. ALDH6 was not present in MCF-7 cells, and these cells were unable to oxidize retinal to RA in culture. When MCF-7 cells were then transfected with ALDH6, they (re)gained the ability to oxidize retinal to RA as well as some ability to synthesize RA when provided with retinol. This suggests that loss of ALDH6 expression is the defect in RA biosynthesis in these cells. Identification of ALDH6 as the retinaldehyde dehydrogenase present in normal human breast epithelia provides the first tool necessary for studying the loss of RA synthetic ability in cancer cells and the relationship of this process to malignant transformation.
Retinoic acid (RA) is the form of vitamin A that controls differentiation and proliferation of epithelia. Our previous work established that normal breast epithelia synthesize RA from retinol, an ability retained by three immortalized but nontumorigenic cell lines but lost in five of six breast cell lines. In this work, we characterize the cause of this defect in one of the lines, the MCF-7 line. We have determined that the immortalized but nontumorigenic cell line, MTSV1.7, capable of synthesizing RA from both retinol and retinal, contains a retinaldehyde dehydrogenase activity for the second step in RA biosynthesis. We have identified it, after isolation, as a previously described enzyme, aldehyde dehydrogenase 6 (ALDH6). Immunohistochemical analysis of normal human breast with antibodies to ALDH6 showed expression of this enzyme in the glandular epithelia colocalized with cellular RA-binding protein type II, a possible marker for certain cells able to synthesize RA. ALDH6 was not present in MCF-7 cells, and these cells were unable to oxidize retinal to RA in culture. When MCF-7 cells were then transfected with ALDH6, they (re)gained the ability to oxidize retinal to RA as well as some ability to synthesize RA when provided with retinol. This suggests that loss of ALDH6 expression is the defect in RA biosynthesis in these cells. Identification of ALDH6 as the retinaldehyde dehydrogenase present in normal human breast epithelia provides the first tool necessary for studying the loss of RA synthetic ability in cancer cells and the relationship of this process to malignant transformation.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.