Anna Suwińska

Nicolaus Copernicus University | umk

Pollen tube growth depends on several complex processes, including exo/endocytosis, cell wall biogenesis, intracellular transport, and cell signaling. Our previous results provided evidence that calreticulin (CRT)—a prominent calcium (Ca2+)-buffering molecular chaperone in the endoplasmic reticulum (ER) lumen—is involved in pollen tube formation an...

Background Pollen development in the anther in angiosperms depends on complicated cellular interactions associated with the expression of gametophytic and sporophytic genes which control fundamental processes during microsporo/gametogenesis, such as exo/endocytosis, intracellular transport, cell signaling, chromatin remodeling, and cell division. M...

Myosin VI (MYO6) is an actin-based motor that has been implicated in a wide range of cellular processes, including endocytosis and the regulation of actin dynamics. MYO6 is crucial for actin/membrane remodeling during the final step of Drosophila spermatogenesis, and MYO6-deficient males are sterile. This protein also localizes to actin-rich struct...

Calreticulin (CRT) is a multifunctional resident endoplasmic reticulum (ER) luminal protein implicated in regulating a variety of cellular processes, including Ca⁠2+ storage/mobilization and protein folding. These multiple functions may be carried out by different CRT genes and protein isoforms. The plant CRT family consist of three genes: CRT1 and...

Calcium (Ca(2+)) plays essential roles in generative reproduction of angiosperms, but the sites and mechanisms of Ca(2+) storage and mobilization during pollen-pistil interactions have not been fully defined. Both external and internal Ca(2+) stores are likely important during male gametophyte communication with the sporophytic and gametophytic cel...

Main conclusion: Calreticulin is involved in stabilization of the tip-focused Ca (2+) gradient and the actin cytoskeleton arrangement and function that is required for several key processes driving Petunia pollen tube tip growth. Although the precise mechanism is unclear, stabilization of a tip-focused calcium (Ca(2+)) gradient seems to be critica...

Key message In germinating pollen grains and growing pollen tubes, CRT is translated on ER membrane-bound ribosomes in the regions where its activity is required for stabilization of tip-focused Ca 2+ gradient. Abstract Pollen tube growth requires coordination of signaling, exocytosis, and actin cytoskeletal organization. Many of these processes ar...

Calcium (Ca(2+)) plays essential roles in plant sexual reproduction, but the sites and the mechanism of Ca(2+) mobile storage during pollen-pistil interactions have not been fully defined. Because the Ca(2+)-buffering protein calreticulin (CRT) is able to bind and sequester Ca(2+), it can serve as a mobile intracellular store of easily releasable C...

Calreticulin (CRT) is a highly conserved and ubiquitously expressed Ca(2+)-binding protein in multicellular eukaryotes. As an endoplasmic reticulum-resident protein, CRT plays a key role in many cellular processes including Ca(2+) storage and release, protein synthesis, and molecular chaperoning in both animals and plants. CRT has long been suggest...

In this study, the transcriptional state and distribution of RNA polymerase II, pre-mRNA splicing machinery elements, and rRNA transcripts were investigated in the sperm cells of Hyacinthus orientalis L. during in vitro pollen tube growth. During the second pollen mitosis, no nascent transcripts were observed in the area of the dividing generative...