puncta adherentia  (Spacek Labs)

Journal: The Journal of Biological Chemistry

Article Title: Mitochondria–plasma membrane interactions and communication

doi: 10.1016/j.jbc.2021.101164

Figure Lengend Snippet: PM–mitochondria interactions in non-CNS and CNS cells. A1 , Fig. 5 from plate 4 in showing the mitochondria-associated junction described by the author in follicular cells of the bat thyroid during late hibernation. Here, two mitochondria are shown from neighboring cells apposed to the PM with highly electrodense regions in between (the mitochondria-associated junction), with their cisterna oriented perpendicular to the PM plane. The arrows point to the close association between the OMM and the PM, X140,000. A2 , Fig. 6 from showing two mitochondria with fibers ( arrow ) on two sides of a desmosome in neighboring cells from the rat thyroid gland, X50,000. A3 , Fig. 4 from showing a mitochondrion of a human Sertoli cell adjacent to a spermatocyte. In this TEM micrograph, the filamentous material ( arrows ) of the desmosomes seem to contact mitochondria, X42800. A4 , Fig. 1 B from showing cardiac myocyte mitochondria closely apposed to caveolae (scale not specified). A5 , Fig. 1 F from showing evidence of increased association of caveola–mitochondria after ischemic preconditioning. Note the tubular extension that contact mitochondria ( arrowhead ), one of them apparently evaginated from the caveolae ( arrow ). The scale bar represents 50 nm. A6 , segment of Fig. 4 in showing an ET image of a T-tubule ( green ) membrane with an invaginating caveolae ( blue ), near a mitochondrion in rabbit ventricular tissue. The scale bar represents 100 nm. All figures were used with permission. B , PM–mitochondria interactions in CNS cells. B1 , section of Fig. 9 in showing the attachment plaque in the anteroventral cochlear nucleus of the cat. In the ending, a row of vesicles ( arrowheads ), overlying dense plaque, and filamentous material extending to mitochondria. The scale bar represents 500 nm. B2 , section of Fig. 12 in showing part of a symmetrical filamentous contact between an axon and a dendrite associated with mitochondria in the thalamic relay nuclei of rats. The white arrow shows a spot-like close membrane interaction suggested to be a GJ. The scale bar represents 100 nm. B3 , Fig. 8 A from showing details of the mitochondria-associated adherens complex (MACs) in the lateral nucleus of the trapezoid body of the cat. This assembly is composed of the punctum adherens ( open arrows ); a mitochondrion often with its side facing the PM flattened and cristae oriented perpendicular to the PM plane; the mitochondria plaque ( small solid arrows ); the vesicular chain ( dotted arrows ) filamentous bands (f) form the puncta adherens to the mitochondrion; and often an associated mitochondrion in the postsynaptic cell. The scale bar represents 200 nm. B4 , Fig. 5 D from showing an ET reconstruction close-up of the MAC in the Calyx of Held of the cat. In dark blue , is the presynaptic membrane; the mitochondria ( green ); microtubules ( blue ); microfilaments ( red filaments); struts ( gold ); the mitochondrial plaque ( purple ); and punctum adherens ( light red on the presynaptic membrane). B5 , Fig. 1 E from showing the organization of mitochondria in photoreceptors of the mouse retina. Mitochondria are arranged in aligned ( black arrowheads ) doublets or triplets between neighboring inner segment regions of photoreceptors. White arrowheads point to membrane projections observed between the inner segments near mitochondria. The scale bar represents 100 nm. B6 , Fig. 6 B in showing the PM–mitochondria bridges in cultured rat astrocytes. This structure is related to endocytic vesicles, most probably, caveolae for their size ( arrow ). It also comprises an electrodense area that seems to connect mitochondria with the PM that coincides with dark spots located within mitochondria. The perpendicular organization of mitochondria cisternae relative to the PM is also observed. The scale bar represents 250 nm. All figures are used with permission. EC, extracellular; ET, electron tomography; GJs, gap junctions; M, mitochondria; PM, plasma membrane; TEM, transmission electron microscopy.

Article Snippet: Similar observations were made by Spacek (1985), showing puncta adherentia and associated mitochondria in the mouse visual cortex ( ).

Techniques: Membrane, Cell Culture, Tomography, Clinical Proteomics, Transmission Assay, Electron Microscopy

Journal: The Journal of Biological Chemistry

Article Title: Mitochondria–plasma membrane interactions and communication

doi: 10.1016/j.jbc.2021.101164

Figure Lengend Snippet: Complexity levels of plasma membrane–mitochondria interactions. A , the most fundamental communication between the PM and mitochondria is mediated by the diffusion of solutes including ions ( i.e. , Ca 2+ or Na + ), second messengers ( i.e. , InsP3), or proteins ( i.e. , signal transducers). This communication is bidirectional, indicated by the double-headed arrow . In orange , an ion-permeable channel. B , early TEM observations mostly in epithelial cells showed the interaction of mitochondria with PM domains such as desmosomes or other adhesion contacts as GJ or puncta adherens. These interactions presented filamentous arrangements ( green ) between desmosomes and mitochondria, highly electrodense regions at the PM, which may include the PM of the neighboring cell, and cisternae perpendicular to the PM plane. These interactions may comprise other mitochondria in the adjoining cell and different distances to the PM ( Fig. 3 , A2 and A3 ) [drawing based on ]. C , mitochondria tethered to the PM in two neighboring cells with highly electrodense regions in between, with their cisterna oriented perpendicular to the PM plane have been reported. This disposition of mitochondria seems to be related to cellular synchronization ( Fig. 3 , A1 and B5 ) [drawing based on ]. D , more elaborated structures have been observed in presynaptic neurons in several CNS regions ( Fig. 3 , B1–B4 ), with several bands between the PM and mitochondria, filamentous structures ( green ), highly electrodense regions at the PM of presynaptic and postsynaptic neurons, flattening of the mitochondria membrane that faces the PM, and perpendicular cisternae to the PM. Occasionally, mitochondria in the postsynaptic cell can be observed close and in front of these structures ( Fig. 3 , B1–B3 ) [drawing based on ]. These structures were observed later by different groups and were named mitochondria adherens complex (MAC) in , the group that also did ET of these structures ( Fig. 3 , B3 and B4 ). E , membrane invaginations ( blue ) extending into the cytoplasm that contact mitochondria have been described in yeast PM and caveolae from myocytes . In the case of yeast, some molecular players of the MECA complex have been elucidated [drawing based on ]. F , caveolae have been implicated in PM–mitochondria interactions ( Fig. 3 A4 , A5 , and B6 ). In cultured astrocytes, we described the PM–mitochondria bridges, consisting of a highly electrodense region between the PM and mitochondria, which is associated with invaginated vesicles ( blue ) with the size of caveolae, flattening of the mitochondria membrane facing the PM, and dots within mitochondria that also present cisternae perpendicular to the PM. These structures mediated the mass transfer from the PM to mitochondria in minutes [drawing based on ]. G , tunneling nanotubes (TNTs) are cellular structures that have been shown to mediate cargo transfer between cells, including mitochondria. The interaction between the PM and mitochondria has not been demonstrated, but it probably occurs ( question mark ) as mitochondria are located at the TNT entry and trespass the PM plane. ET, electron tomography; PM, plasma membrane; TEM, transmission electron microscopy.

Article Snippet: Similar observations were made by Spacek (1985), showing puncta adherentia and associated mitochondria in the mouse visual cortex ( ).

Techniques: Clinical Proteomics, Membrane, Diffusion-based Assay, Cell Culture, Tomography, Transmission Assay, Electron Microscopy

Journal: The Journal of Biological Chemistry

Article Title: Mitochondria–plasma membrane interactions and communication

doi: 10.1016/j.jbc.2021.101164

Figure Lengend Snippet: Glossary of some cell biology terms in bold font used in this text

Article Snippet: Similar observations were made by Spacek (1985), showing puncta adherentia and associated mitochondria in the mouse visual cortex ( ).

Techniques: Phospho-proteomics