title: Conventional and novel Gγ protein families constitute the heterotrimeric G-protein signaling network in soybean.
abstract: Heterotrimeric G-proteins comprised of Gα, Gβ and Gγ proteins are important signal transducers in all eukaryotes. The Gγ protein of the G-protein heterotrimer is crucial for its proper targeting at the plasma membrane and correct functioning. Gγ proteins are significantly smaller and more diverse than the Gα and Gβ proteins. In model plants Arabidopsis and rice that have a single Gα and Gβ protein, the presence of two canonical Gγ proteins provide some diversity to the possible heterotrimeric combinations. Our recent analysis of the latest version of the soybean genome has identified ten Gγ proteins which belong to three distinct families based on their C-termini. We amplified the full length cDNAs, analyzed their detailed expression profile by quantitative PCR, assessed their localization and performed yeast-based interaction analysis to evaluate interaction specificity with different Gβ proteins. Our results show that ten Gγ genes are retained in the soybean genome and have interesting expression profiles across different developmental stages. Six of the newly identified proteins belong to two plant-specific Gγ protein families. Yeast-based interaction analyses predict some degree of interaction specificity between different Gβ and Gγ proteins. This research thus identifies a highly diverse G-protein network from a plant species. Homologs of these novel proteins have been previously identified as QTLs for grain size and yield in rice.
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, Missouri, United States of America.
authors.forename: Swarup Roy
authors.initials: SR
authors.lastname: Choudhury
authors.forename: Naveen C
authors.initials: NC
authors.lastname: Bisht
authors.forename: Rheannon
authors.initials: R
authors.lastname: Thompson
authors.forename: Oleg
authors.initials: O
authors.lastname: Todorov
authors.forename: Sona
authors.initials: S
authors.lastname: Pandey
mesh_terms: D000595:Amino Acid Sequence; D005091:Exons / Q000235:genetics; D044387:GTP-Binding Protein beta Subunits / Q000235:genetics / Q000378:metabolism; D044388:GTP-Binding Protein gamma Subunits / Q000737:chemistry / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000235:genetics; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D060066:Protein Interaction Maps; D021381:Protein Transport; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D016415:Sequence Alignment; D015398:Signal Transduction / Q000235:genetics; D013025:Glycine max / Q000235:genetics / Q000378:metabolism*
chemical_list: D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D010940:Plant Proteins