Meiotic chromosome homology search involves modifications of the nuclear envelope protein Matefin/SUN-1.
Genome haploidization during meiosis depends on recognition and association of parental homologous chromosomes. The C. elegans SUN/KASH domain proteins Matefin/SUN-1 and ZYG-12 have a conserved role in this process. They bridge the nuclear envelope, connecting the cytoplasm and the nucleoplasm to transmit forces that allow chromosome movement and homolog pairing and prevent nonhomologous synapsis. Here, we show that Matefin/SUN-1 forms rapidly moving aggregates at putative chromosomal attachment sites in the meiotic transition zone (TZ). We analyzed requirements for aggregate formation and identified multiple phosphotarget residues in the nucleoplasmic domain of Matefin/SUN-1. These CHK-2 dependent phosphorylations occur in leptotene/zygotene, diminish during pachytene and are involved in pairing. Mimicking phosphorylation causes an extended TZ and univalents at diakinesis. Our data suggest that the properties of the nuclear envelope are altered during the time window when homologs are sorted and Matefin/SUN-1 aggregates form, thereby controling the movement, homologous pairing and interhomolog recombination of chromosomes.
Penkner
Alexandra M
AM
Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, 1030-Vienna, Austria. alexandra.penkner@univie.ac.at
Fridkin
Alexandra
A
Gloggnitzer
Jiradet
J
Baudrimont
Antoine
A
Machacek
Thomas
T
Woglar
Alexander
A
Csaszar
Edina
E
Pasierbek
Pawel
P
Ammerer
Gustav
G
Gruenbaum
Yosef
Y
Jantsch
Verena
V
D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000378:metabolism*; D064447:Checkpoint Kinase 2; D023902:Chromosome Pairing; D002875:Chromosomes / Q000378:metabolism; D008540:Meiosis; D049469:Meiotic Prophase I; D008870:Microtubules / Q000378:metabolism*; D009154:Mutation; D009685:Nuclear Envelope / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000378:metabolism*; D012694:Serine / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D018160:Receptors, Cytoplasmic and Nuclear; C514114:sun-1 protein, C elegans; D012694:Serine; D011494:Protein Kinases; D064447:Checkpoint Kinase 2; C444421:CHK-2 protein, C elegans