PMID- 10613905
OWN - NLM
STAT- MEDLINE
DCOM- 20000204
LR  - 20190508
IS  - 0021-9525 (Print)
IS  - 0021-9525 (Linking)
VI  - 147
IP  - 7
DP  - 1999 Dec 27
TI  - Abnormal features in skeletal muscle from mice lacking mitsugumin29.
PG  - 1473-80
AB  - Physiological roles of the members of the synaptophysin family, carrying four
      transmembrane segments and being basically distributed on intracellular membranes
      including synaptic vesicles, have not been established yet. Recently,
      mitsugumin29 (MG29) was identified as a novel member of the synaptophysin family 
      from skeletal muscle. MG29 is expressed in the junctional membrane complex
      between the cell surface transverse (T) tubule and the sarcoplasmic reticulum
      (SR), called the triad junction, where the depolarization signal is converted to 
      Ca(2+) release from the SR. In this study, we examined biological functions of
      MG29 by generating knockout mice. The MG29-deficient mice exhibited normal health
      and reproduction but were slightly reduced in body weight. Ultrastructural
      abnormalities of the membranes around the triad junction were detected in
      skeletal muscle from the mutant mice, i.e., swollen T tubules, irregular SR
      structures, and partial misformation of triad junctions. In the mutant muscle,
      apparently normal tetanus tension was observed, whereas twitch tension was
      significantly reduced. Moreover, the mutant muscle showed faster decrease of
      twitch tension under Ca(2+)-free conditions. The morphological and functional
      abnormalities of the mutant muscle seem to be related to each other and indicate 
      that MG29 is essential for both refinement of the membrane structures and
      effective excitation-contraction coupling in the skeletal muscle triad junction. 
      Our results further imply a role of MG29 as a synaptophysin family member in the 
      accurate formation of junctional complexes between the cell surface and
      intracellular membranes.
FAU - Nishi, M
AU  - Nishi M
AD  - Department of Pharmacology, Faculty of Medicine, University of Tokyo, Tokyo
      113-8654, Japan.
FAU - Komazaki, S
AU  - Komazaki S
FAU - Kurebayashi, N
AU  - Kurebayashi N
FAU - Ogawa, Y
AU  - Ogawa Y
FAU - Noda, T
AU  - Noda T
FAU - Iino, M
AU  - Iino M
FAU - Takeshima, H
AU  - Takeshima H
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Cell Biol
JT  - The Journal of cell biology
JID - 0375356
RN  - 0 (Mg29 protein, mouse)
RN  - 0 (Muscle Proteins)
RN  - 0 (Synaptophysin)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Body Weight/genetics
MH  - Hindlimb/abnormalities/physiopathology/ultrastructure
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Mice, Knockout
MH  - Molecular Sequence Data
MH  - Multigene Family
MH  - Muscle Contraction/genetics
MH  - Muscle Proteins/*deficiency/*genetics/physiology
MH  - Muscle, Skeletal/*abnormalities/physiopathology/ultrastructure
MH  - Synaptophysin/*analogs & derivatives/deficiency/genetics/physiology
PMC - PMC2174246
EDAT- 1999/12/30 00:00
MHDA- 1999/12/30 00:01
CRDT- 1999/12/30 00:00
PHST- 1999/12/30 00:00 [pubmed]
PHST- 1999/12/30 00:01 [medline]
PHST- 1999/12/30 00:00 [entrez]
AID - 10.1083/jcb.147.7.1473 [doi]
PST - ppublish
SO  - J Cell Biol. 1999 Dec 27;147(7):1473-80. doi: 10.1083/jcb.147.7.1473.