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.
Institute of Molecular Biology, University of Oregon, Eugene, OR 97403-1229, USA. rcapaldi@oregon.uoregon.edu
Roderick A
RA
Capaldi
Robert
R
Aggeler
Robert
R
Gilkerson
George
G
Hanson
Michelle
M
Knowles
Andrew
A
Marcus
Daciana
D
Margineantu
Michael
M
Marusich
James
J
Murray
Devin
D
Oglesbee
S James
SJ
Remington
Rodrigue
R
Rossignol
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