A replicating module as the unit of mitochondrial structure and functioning.
The mitochondrion within human cells in tissue culture is pleomorphic and highly dynamic. The organelle mass can exist as thousands of small ovoids or as one continuous reticulum. In either state, the mitochondrial mass is in constant thermal motion, as well as moving in approximately 0.8-microm jumps that are determined by, and related to, attachments with cytoskeletal elements. Many protein complexes, such as the pyruvate dehydrogenase (PDH) complex and DNA containing nucleoids, are dispersed through the mass and as though fixed by attachments to membranes, such that they can become distributed to all of the individual small ovoid mitochondria when the reticulum becomes fragmented. This leads us to propose that a replicating module is the repeating unit of mitochondrial structure. Studies to examine heterogeneity of functioning within the organelle mass are briefly reviewed.
Capaldi
Roderick A
RA
Institute of Molecular Biology, University of Oregon, Eugene, OR 97403-1229, USA. rcapaldi@oregon.uoregon.edu
Aggeler
Robert
R
Gilkerson
Robert
R
Hanson
George
G
Knowles
Michelle
M
Marcus
Andrew
A
Margineantu
Daciana
D
Marusich
Michael
M
Murray
James
J
Oglesbee
Devin
D
Remington
S James
SJ
Rossignol
Rodrigue
R
D015374:Biosensing Techniques; D003599:Cytoskeleton / Q000737:chemistry / Q000502:physiology*; D004272:DNA, Mitochondrial / Q000737:chemistry; D049452:Green Fluorescent Proteins; D006801:Humans; D007425:Intracellular Membranes / Q000737:chemistry / Q000502:physiology*; D008164:Luminescent Proteins; D008565:Membrane Proteins / Q000737:chemistry; D008928:Mitochondria / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D008938:Mitosis; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry; D016196:S Phase; D014407:Tumor Cells, Cultured
D004272:DNA, Mitochondrial; D008164:Luminescent Proteins; D008565:Membrane Proteins; D011768:Pyruvate Dehydrogenase Complex; D049452:Green Fluorescent Proteins