Immunolocalization and histochemical evidence for the association of two different Arabidopsis annexins with secretion during early seedling growth and development.

Annexins are a multigene, multifunctional family of calcium-dependent, membrane-binding proteins found in animal and plant cells. In plants, annexins have been localized in the cytoplasm and at the cell periphery of highly secretory cell types, and in the tip region of polarly growing cells. Consequently, one proposed function for annexins in plant cells is participation in the Golgi-mediated secretion of new wall materials.

Redistribution of annexin in gravistimulated pea plumules.

We used immunocytochemistry to investigate the effects of gravistimulation on annexin localization in etiolated pea plumule shoots. In longitudinal sections, an asymmetric annexin immunostaining pattern was observed in a defined group of cells located just basipetal to apical meristems at the main shoot apex and at all of the axillary buds, an area classically referred to as the leaf gap. The pattern was observed using both protein-A-purified anti-annexin and affinity-purified anti-annexin antibodies for the immunostaining.

Immunological and biochemical evidence for nuclear localization of annexin in peas.

Immunofluorescent localization of annexins using an anti-pea annexin polyclonal antibody (anti-p35) in pea (Pisum sativum) leaf and stem epidermal peels showed staining of the nuclei and the cell periphery. Nuclear staining was also seen in cell teases prepared from pea plumules. The amount of nuclear stain was reduced both by fixation time and by dehydration and organic solvent treatment.

Immunolocalization of an annexin-like protein in corn.

Although calcium has been proposed to be an important regulatory element in plant gravitropic growth, as yet no specific function of Ca2+ in growth regulation has been discovered. Our recent studies on a Ca(2+)-binding protein in pea seedlings called p35 indicate that it is a member of the annexin family of proteins and may play a key role in growth regulation through its function in delivering polysaccharides needed for wall construction. We previously reported the isolation of p35 from pea plumules and the production of polyclonal antibodies to it.

The major nucleoside triphosphatase in pea (Pisum sativum L.) nuclei and in rat liver nuclei share common epitopes also present in nuclear lamins.

The major nucleoside triphosphatase (NTPase) activities in mammalian and pea (Pisum sativum L.) nuclei are associated with enzymes that are very similar both biochemically and immunochemically. The major NTPase from rat liver nuclei appears to be a 46-kD enzyme that represents the N-terminal portion of lamins A and C, two lamina proteins that apparently arise from the same gene by alternate splicing.

Purification and immunolocalization of an annexin-like protein in pea seedlings.

As part of a study to identify potential targets of calcium action in plant cells, a 35-kDa, annexin-like protein was purified from pea (Pisum sativum L.) plumules by a method used to purify animal annexins. This protein, called p35, binds to a phosphatidylserine affinity column in a calcium-dependent manner and binds (45)Ca(2+) in a dot-blot assay.

Purification and immunolocalization of an annexin-like protein in pea seedlings.

As part of a study to identify potential targets of calcium action in plant cells, a 35-kDa, annexin-like protein was purified from pea (Pisum sativum L.) plumules by a method used to purify animal annexins. This protein, called p35, binds to a phosphatidylserine affinity column in a calcium-dependent manner and binds 45Ca2+ in a dot-blot assay.

Partial purification and characterization of a Ca(2+)-dependent protein kinase from pea nuclei.

Almost all the Ca(2+)-dependent protein kinase activity in nuclei purified from etiolated pea (Pisum sativum, L.) plumules is present in a single enzyme that can be extracted from chromatin by 0.3 molar NaCl.

Production and characterization of monoclonal antibodies to wall-localized peroxidases from corn seedlings.

A library of 22 hybridomas, which make antibodies to soluble wall antigens from the coleoptiles and primary leaves of etiolated corn (Zea mays L.) seedlings, was raised and cloned three times by limit dilution to assure monoclonal growth and stability. Two of these hybridomas made immunoglobulin G antibodies, designated mWP3 and mWP19, which both effectively immunoprecipitated peroxidase activity from crude and partially purified preparations of wall peroxidases.

Distribution of calmodulin in pea seedlings: Immunocytochemical localization in plumules and root apices.

Immunofluorescence techniques have been used to study the distribution of calmodulin in several tissues in young etiolated pea (Pisum sativum L.) seedlings. A fairly uniform staining was seen in the nucleoplasm and background cytoplasm of most cell types.

Distribution of calmodulin in pea seedlings: immunocytochemical localization in plumules and root apices.

Immunofluorescence techniques have been used to study the distribution of calmodulin in several tissues in young etiolated pea (Pisum sativum L.) seedlings. A fairly uniform staining was seen in the nucleoplasm and background cytoplasm of most cell types.

Distribution of calmodulin in corn seedlings: immunocytochemical localization in coleoptiles and root apices.

Immunofluorescence techniques have been used to study the distribution of calmodulin in several tissues in etiolated corn (Zea mays, var. Bear Hybrid) seedlings. Uniform staining was seen in the background cytoplasm of most cell types.

Cellular and subcellular localization of calcium in gravistimulated corn roots.

Antimonate staining procedures and energy dispersive X-ray micro-analytical techniques were used to determine the patterns of localization of calcium in nonstimulated and gravistimulated corn roots. In horizontally positioned roots within the region of the developing bend there was a change in the staining from that principally localized within cells of the stele to asymmetric staining within the vacuoles of the cortical cells along the upper root surface. There was little staining in the walls.

Oncornavirus modification of the Golgi apparatus.

Two virus system, The Friend leukaemia virus (FLV) and the Rous sarcoma virus (RSV), were introduced into tissue both in vitro and in vivo. Both brought about substantial modification of the activity of the Golgi apparatus detectable as such by specific radioautographic studies. This modification was accompanied by changes in the development and social behaviour of the cells with some differences being detectable between the in vivo and in vitro studies.