title: Cellular distribution of calmodulin and calmodulin-binding proteins in Vicia faba L.
abstract: The distribution of calmodulin (CaM) and CaM-binding proteins within Vicia faba was investigated.  Both CaM and CaM-binding proteins were found to be differentially distributed among organs, tissues, and protoplast types.  CaM levels, on a per protein basis, were found to be the highest in leaf epidermis, containing 3-fold higher levels of CaM than in total leaf.  Similarly, guard cell and epidermal cell protoplasts were also found to have higher levels of CaM than mesophyll cell protoplasts.  125I-CaM blot overlay assays were performed to qualitatively examine CaM-binding proteins in these protoplast types as well as in whole tissues and organs.  CaM-binding proteins with Mr 52,000, 78,000, and 115,000 were common in all metabolically active plant parts.  Unique CaM-binding protein bands were detected in guard cell protoplasts (Mr 39,000, 88,000), stems (Mr 45,000, 60,000, 64,000), and roots (Mr 62,000), suggesting the presence of specialized CaM-dependent processes in these cells and organs.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138.
authors.forename: V
authors.initials: V
authors.lastname: Ling
authors.forename: S M
authors.initials: SM
authors.lastname: Assmann
mesh_terms: D002147:Calmodulin / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000032:analysis* / Q000378:metabolism; D004586:Electrophoresis; D007887:Fabaceae / Q000737:chemistry* / Q000166:cytology* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D010946:Plants, Medicinal; D011523:Protoplasts / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D010940:Plant Proteins