Structure of (Na+,K+)-ATPase as revealed by electron microscopy and image processing.

Mohraz, Manijeh; Smith, Paul

doi:10.1083/jcb.98.5.1836

Cited by 27 publications

(12 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, since the shadowing does not give detail of the molecular shape, we cannot yet tell whether these orderly arrangements are truly monomeric (i.e., with all units facing in one direction), or are distorted dimeric arrangements (i.e., with paired units facing each other). The Na,K ATPase also forms a third pattern, interpreted as dimeric, which has unit cell dimensions of 5.5 x 16.1 nm (Mohraz and Smith, 1984). A comparable arrangement has not been described in Ca ATPase, but we have found two orderly areas with 13 and 15 nm spacings between rows.…”

Section: Discussionsupporting

confidence: 78%

Ordered arrays of Ca2+-ATPase on the cytoplasmic surface of isolated sarcoplasmic reticulum

Ferguson¹,

Franzini‐Armstrong²,

Castellani³

et al. 1985

Biophysical Journal

View full text Add to dashboard Cite

Isolated sarcoplasmic reticulum (SR) vesicles with polymerized calcium pump protein were freeze-dried and rotary shadowed following uranyl acetate stabilization. This technique allows direct observation of a single side of the vesicle without requiring optical filtering. The heads of individual ATPase molecules, projecting above the cytoplasmic surface, are clearly resolved in the replicas. Ca ATPase molecules form extensive arrays in vanadate-treated, rabbit SR vesicles and in gently isolated, native SR vesicles from scallop. Gentle isolation results in limited areas of orderly structure in native SR isolated from vertebrate muscles. Special attention is given to the effect of various shadow thicknesses on the appearance of the heads. This information is essential to the interpretation of images in the accompanying paper (Franzini-Armstrong, C., and D.J. Ferguson, 1985, Biophys. J., 48:607-615).

show abstract

Section: Discussionsupporting

confidence: 78%

Ordered arrays of Ca2+-ATPase on the cytoplasmic surface of isolated sarcoplasmic reticulum

Ferguson¹,

Franzini‐Armstrong²,

Castellani³

et al. 1985

Biophysical Journal

View full text Add to dashboard Cite

show abstract

“…This is close enough to the 5.6 nm of the crystallized g-fl monomer of E2-(H+,K+)-ATPase [9]. Moreover, the shadow shape looks similar to the heartshaped image of an ATPase monomer crystallized in a membrane bilayer [6]. (table III)) are shorter than the crystallized ¢¢2"fl2 width (a = 16.1 nm) [6].…”

Section: Discussionsupporting

confidence: 65%

“…Moreover, the shadow shape looks similar to the heartshaped image of an ATPase monomer crystallized in a membrane bilayer [6]. (table III)) are shorter than the crystallized ¢¢2"fl2 width (a = 16.1 nm) [6]. Could A and The fractured membrane surface is grey, the Pt-C cap of the particle is white and the particle shadow black.…”

Section: Discussionmentioning

confidence: 57%

Statistical evidence for two major proteins in freeze‐fractured gastric parietal cell tubulovesicles and canaliculus

Maccario¹,

Péranzi²,

Bayle³

et al. 1994

Biology of the Cell

View full text Add to dashboard Cite

In a previous work, resting and acid-secreting rabbit gastric mucosa were freeze-fractured and shadowed at 45 degrees with Pt-C. The shadow widths of proteic particles of tubulovesicle and canaliculus membranes were measured and compared. It was concluded that the frequency distributions of widths are significantly different in resting and secreting membranes and that each distribution accounts for several subpopulations of homogeneous particles. In the present study, an attempt is made to describe the experimental distributions as a mixture of those of two major proteins, say A and B and their aggregates (AA, AB and BB). The modelling, although simple, gave a very satisfactory statistical fit between observed and computed distributions. The comparison of parameters calculated from histamine and ranitidine experimental data further improves the fits and finally, component A accounts for 69% of the particles. Most replica of A particles are heart-shaped and the median shadow widths are 6.1 and 6.8 nm in canaliculus and tubulovesicles respectively. The component B accounts for 31% of the particles. They mainly appear as small barrels and the median shadow widths are 8.8 and 10.3 nm in canaliculus and tubulovesicles respectively. According to calculated parameters and observed particle replica, the onset of secretion does not change the relative ratio of proteins but changes their shapes. Component A should be the (H+,K+)-ATPase whereas debate on the identity of B is wide open.

show abstract

“…The intracellular face protrudes -50 A from the bilayer and contains ATP binding sites (7,25) and functional sulfhydryls significantly removed from the bilayer by ~30-40 A (16). These structural studies and others (18,26) suggest that the a subunit has a sufficiently large cytoplasmic domain to permit it to interact directly with cytosolic proteins. Such interaction could possibly be important in maintaining its distribution in the plasma membrane (1).…”

mentioning

confidence: 80%

The lateral mobility of the (Na+,K+)-dependent ATPase in Madin-Darby canine kidney cells.

Jesaitis¹,

Yguerabide²

1986

The Journal of Cell Biology

View full text Add to dashboard Cite

Abstract. Fluorescence microphotolysis (recovery after photobleaching) was used to determine the lateral mobility of the (Na+,K+)ATPase and a fluorescent lipid analogue in the plasma membrane of MadinDarby canine kidney (MDCK) cells at different stages of development. Fluorescein-conjugated Fab' fragments prepared from rabbit anti-dog (Na+,K+)ATPase antibodies (IgG) and 5-(N-hexadecanoyl)aminofluorescein (HEDAF) were used to label the plasma membrane of confluent and subconfluent cultures of MDCK cells. Fractional fluorescence recovery was 50% and 80-90% for the protein and lipid probes, respectively, and was independent of developmental stage. The estimated diffusion constants of the mobile fraction were -5 × l0 -1° cm2/s for the (Na+,K+)ATPase and ~2 × 10 -9 cm2/s for HEDAF. Only HEDAF diffusion showed dependency on developmental stage in that D for confluent cells was approximately twice that for subconfluent cells. These results indicate that (Na+,K+)ATPase is 50% immobilized in all developmental stages, whereas lipids in confluent MDCK cells are more mobile than in subconfluent cells. They suggest, furthermore, that the degree of immobilization of the (Na+,K+)ATPase is insufficient to explain its polar distribution, and they support restricted mobility of the ATPase through the tight junctions as the likely mechanism for preventing the diffusion of this protein into the apical domain of the plasma membrane in confluent cell cultures.

show abstract

Structure of (Na+,K+)-ATPase as revealed by electron microscopy and image processing.

Cited by 27 publications

References 22 publications

Ordered arrays of Ca2+-ATPase on the cytoplasmic surface of isolated sarcoplasmic reticulum

Ordered arrays of Ca2+-ATPase on the cytoplasmic surface of isolated sarcoplasmic reticulum

Statistical evidence for two major proteins in freeze‐fractured gastric parietal cell tubulovesicles and canaliculus

The lateral mobility of the (Na+,K+)-dependent ATPase in Madin-Darby canine kidney cells.

Contact Info

Product

Resources

About