AGB1 GB1 Guanine nucleotide-binding protein subunit beta Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein- effector interaction. Together with GCR1 and GPA1, acts as a negative regulator of ABA during seed germination and early seedling development. MSVSELKERHAVATETVNNLRDQLRQRRLQLLDTDVARYSAAQGRTRVSFGATDLVCCRTLQGHTGKVYSLDWTPERNRIVSASQDGRLIVWNALTSQKTHAIKLPCAWVMTCAFSPNGQSVACGGLDSVCSIFSLSSTADKDGTVPVSRMLTGHRGYVSCCQYVPNEDAHLITSSGDQTCILWDVTTGLKTSVFGGEFQSGHTADVLSVSISGSNPNWFISGSCDSTARLWDTRAASRAVRTFHGHEGDVNTVKFFPDGYRFGTGSDDGTCRLYDIRTGHQLQVYQPHGDGENGPVTSIAFSVSGRLLFAGYASNNTCYVWDTLLGEVVLDLGLQQDSHRNRISCLGLSADGSALCTGSWDSNLKIWAFGGHRRVI transducin At4g34460 T4L20.40 377 GBB_ARATH