TY  - JOUR
A1  - Dunce, James M.
A1  - Milburn, Amy E.
A1  - Gurusaran, Manickam
A1  - da Cruz, Irene
A1  - Sen, Lee T.
A1  - Benavente, Ricardo
A1  - Davies, Owen R.
T1  - Structural basis of meiotic telomere attachment to the nuclear envelope by MAJIN-TERB2-TERB1
JF  - Nature Communications
N2  - Meiotic chromosomes undergo rapid prophase movements, which are thought to facilitate the formation of inter-homologue recombination intermediates that underlie synapsis, crossing over and segregation. The meiotic telomere complex (MAJIN, TERB1, TERB2) tethers telomere ends to the nuclear envelope and transmits cytoskeletal forces via the LINC complex to drive these rapid movements. Here, we report the molecular architecture of the meiotic telomere complex through the crystal structure of MAJIN-TERB2, together with light and X-ray scattering studies of wider complexes. The MAJIN-TERB2 2:2 hetero-tetramer binds strongly to DNA and is tethered through long flexible linkers to the inner nuclear membrane and two TRF1-binding 1:1 TERB2-TERB1 complexes. Our complementary structured illumination microscopy studies and biochemical findings reveal a telomere attachment mechanism in which MAJIN-TERB2-TERB1 recruits telomere-bound TRF1, which is then displaced during pachytene, allowing MAJIN-TERB2-TERB1 to bind telomeric DNA and form a mature attachment plate.
KW  - DNA
KW  - meiosis
KW  - proteins
KW  - super-resolution microscopy
KW  - X-ray crystallography
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226416
VL  - 9
ER  - 
TY  - JOUR
A1  - Scheib, Ulrike
A1  - Broser, Matthias
A1  - Constantin, Oana M.
A1  - Yang, Shang
A1  - Gao, Shiqiang
A1  - Mukherjee, Shatanik
A1  - Stehfest, Katja
A1  - Nagel, Georg
A1  - Gee, Christine E.
A1  - Hegemann, Peter
T1  - Rhodopsin-cyclases for photocontrol of cGMP/cAMP and 2.3 Å structure of the adenylyl cyclase domain
JF  - Nature Communications
N2  - The cyclic nucleotides cAMP and cGMP are important second messengers that orchestrate fundamental cellular responses. Here, we present the characterization of the rhodopsinguanylyl cyclase from Catenaria anguillulae (CaRhGC), which produces cGMP in response to green light with a light to dark activity ratio > 1000. After light excitation the putative signaling state forms with tau = 31 ms and decays with tau = 570 ms. Mutations (up to 6) within the nucleotide binding site generate rhodopsin-adenylyl cyclases (CaRhACs) of which the double mutated YFP-CaRhAC (E497K/C566D) is the most suitable for rapid cAMP production in neurons. Furthermore, the crystal structure of the ligand-bound AC domain (2.25 angstrom) reveals detailed information about the nucleotide binding mode within this recently discovered class of enzyme rhodopsin. Both YFP-CaRhGC and YFP-CaRhAC are favorable optogenetic tools for non-invasive, cell-selective, and spatio-temporally precise modulation of cAMP/cGMP with light.
KW  - Enzymes
KW  - Molecular biophysics
KW  - Molecular neuroscience
KW  - X-ray crystallography
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228517
VL  - 9
ER  -