Isoforms of gelsolin from lobster striated muscles differ in calcium-dependence
Standard
Isoforms of gelsolin from lobster striated muscles differ in calcium-dependence. / Unger, Andreas; Brunne, Bianka; Hinssen, Horst.
in: ARCH BIOCHEM BIOPHYS, Jahrgang 536, Nr. 1, 01.08.2013, S. 38-45.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
Harvard
APA
Vancouver
Bibtex
}
RIS
TY - JOUR
T1 - Isoforms of gelsolin from lobster striated muscles differ in calcium-dependence
AU - Unger, Andreas
AU - Brunne, Bianka
AU - Hinssen, Horst
N1 - Copyright © 2013 Elsevier Inc. All rights reserved.
PY - 2013/8/1
Y1 - 2013/8/1
N2 - Two distinct isoforms of the Ca-dependent actin filament severing protein gelsolin were identified in cross-striated muscles of the American lobster. The variants (termed LG1 and LG2) differ by an extension of 18 AA at the C-terminus of LG1, and by two substitutions at AA735 and AA736, the two C-terminal amino acids of LG2. Functional comparison of the isolated and purified proteins revealed gelsolin-typical properties for both with differences in Ca(2+)-sensitivity, LG2 being activated at significant lower Ca-concentration than LG1: Half maximal activation for both filament severing and G-actin binding was ∼4×10(-7)M Ca(2+) for LG2 vs. ∼2×10(-6)M Ca(2+) for LG1. This indicates a differential activation for the two isoproteins in vivo where they are present in almost equal amounts in the muscle cell. Structure prediction modeling on the basis of the known structure of mammalian gelsolin shows that LG2 lacks the C-terminal alpha-helix which is involved in contact formation between domains G6 and G2. In both mammalian gelsolin and LG1, this "latch bridge" is assumed to play a critical role in Ca(2+)-activation by keeping gelsolin in a closed, inactive conformation at low [Ca(2+)]. In LG2, the reduced contact between G6 and G2 may be responsible for its activation at low Ca(2+)-concentration.
AB - Two distinct isoforms of the Ca-dependent actin filament severing protein gelsolin were identified in cross-striated muscles of the American lobster. The variants (termed LG1 and LG2) differ by an extension of 18 AA at the C-terminus of LG1, and by two substitutions at AA735 and AA736, the two C-terminal amino acids of LG2. Functional comparison of the isolated and purified proteins revealed gelsolin-typical properties for both with differences in Ca(2+)-sensitivity, LG2 being activated at significant lower Ca-concentration than LG1: Half maximal activation for both filament severing and G-actin binding was ∼4×10(-7)M Ca(2+) for LG2 vs. ∼2×10(-6)M Ca(2+) for LG1. This indicates a differential activation for the two isoproteins in vivo where they are present in almost equal amounts in the muscle cell. Structure prediction modeling on the basis of the known structure of mammalian gelsolin shows that LG2 lacks the C-terminal alpha-helix which is involved in contact formation between domains G6 and G2. In both mammalian gelsolin and LG1, this "latch bridge" is assumed to play a critical role in Ca(2+)-activation by keeping gelsolin in a closed, inactive conformation at low [Ca(2+)]. In LG2, the reduced contact between G6 and G2 may be responsible for its activation at low Ca(2+)-concentration.
KW - Actins
KW - Amino Acid Sequence
KW - Animals
KW - Arthropod Proteins
KW - Calcium
KW - Gelsolin
KW - Models, Molecular
KW - Molecular Sequence Data
KW - Muscle, Striated
KW - Nephropidae
KW - Protein Conformation
KW - Protein Isoforms
KW - Protein Structure, Secondary
KW - RNA, Messenger
U2 - 10.1016/j.abb.2013.05.005
DO - 10.1016/j.abb.2013.05.005
M3 - SCORING: Journal article
C2 - 23707758
VL - 536
SP - 38
EP - 45
JO - ARCH BIOCHEM BIOPHYS
JF - ARCH BIOCHEM BIOPHYS
SN - 0003-9861
IS - 1
ER -