Na,K-ATPase subunit beta1 knock-in prevents lethality of beta2 deficiency in mice
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Na,K-ATPase subunit beta1 knock-in prevents lethality of beta2 deficiency in mice. / Weber, P; Bartsch, U; Schachner, M; Montag, D.
In: J NEUROSCI, Vol. 18, No. 22, 15.11.1998, p. 9192-203.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - Na,K-ATPase subunit beta1 knock-in prevents lethality of beta2 deficiency in mice
AU - Weber, P
AU - Bartsch, U
AU - Schachner, M
AU - Montag, D
PY - 1998/11/15
Y1 - 1998/11/15
N2 - The beta2 subunit of the Na,K-ATPase displays functional properties of both an integral constituent of an ion pump and an adhesion and neurite outgrowth-promoting molecule in vitro. To investigate whether the beta1 subunit of the Na,K-ATPase can functionally substitute for the beta2 isoform in vivo, we have generated beta2/beta1 knock-in mice by homologous recombination in embryonic stem cells. In beta2/beta1 knock-in mice, expression of beta2 was abolished, whereas beta1 mRNA expression from the mutated gene amounted to approximately 15% of the normal expression of beta2 in the adult mouse brain and prevented the juvenile lethality observed for beta2 null mutant mice. In contrast to beta2 null mutant mice, the overall morphological structure of all analyzed brain regions was normal. By immunohistochemical analysis, beta1 expression was detected in photoreceptor cells in the retina of knock-in mice at an age when expression of beta1 and beta2, respectively, is downregulated and persisting in the wild-type mice. Morphological analysis by light and electron microscopy revealed a progressive degeneration of photoreceptor cells. Apoptotic death of photoreceptor cells determined quantitatively by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis increased in beta2/beta1 knock-in mice with age. These observations suggest that the beta1 subunit of the Na,K-ATPase can substitute sufficiently, at least in certain cell types, for the role of the beta2 subunit as a component of a functional Na,K-ATPase, but they do not allow us to determine the possible role of the beta2 subunit as an adhesion molecule in vivo.
AB - The beta2 subunit of the Na,K-ATPase displays functional properties of both an integral constituent of an ion pump and an adhesion and neurite outgrowth-promoting molecule in vitro. To investigate whether the beta1 subunit of the Na,K-ATPase can functionally substitute for the beta2 isoform in vivo, we have generated beta2/beta1 knock-in mice by homologous recombination in embryonic stem cells. In beta2/beta1 knock-in mice, expression of beta2 was abolished, whereas beta1 mRNA expression from the mutated gene amounted to approximately 15% of the normal expression of beta2 in the adult mouse brain and prevented the juvenile lethality observed for beta2 null mutant mice. In contrast to beta2 null mutant mice, the overall morphological structure of all analyzed brain regions was normal. By immunohistochemical analysis, beta1 expression was detected in photoreceptor cells in the retina of knock-in mice at an age when expression of beta1 and beta2, respectively, is downregulated and persisting in the wild-type mice. Morphological analysis by light and electron microscopy revealed a progressive degeneration of photoreceptor cells. Apoptotic death of photoreceptor cells determined quantitatively by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis increased in beta2/beta1 knock-in mice with age. These observations suggest that the beta1 subunit of the Na,K-ATPase can substitute sufficiently, at least in certain cell types, for the role of the beta2 subunit as a component of a functional Na,K-ATPase, but they do not allow us to determine the possible role of the beta2 subunit as an adhesion molecule in vivo.
KW - Amino Acid Sequence
KW - Animals
KW - Apoptosis
KW - Cell Adhesion Molecules
KW - Homeostasis
KW - Immunohistochemistry
KW - In Situ Nick-End Labeling
KW - Mice
KW - Mice, Mutant Strains
KW - Microscopy, Electron
KW - Molecular Sequence Data
KW - Mutagenesis
KW - Neuroglia
KW - Phenotype
KW - Photoreceptor Cells, Vertebrate
KW - Retinitis Pigmentosa
KW - Sodium-Potassium-Exchanging ATPase
KW - Stem Cells
KW - Journal Article
M3 - SCORING: Journal article
C2 - 9801359
VL - 18
SP - 9192
EP - 9203
JO - J NEUROSCI
JF - J NEUROSCI
SN - 0270-6474
IS - 22
ER -