High impact information on GPB2

• Gpb1 and Gpb2 lack the seven WD-40 repeats found in Gbeta subunits and instead contain seven kelch repeats implicated in protein-protein interactions [1].
• Indeed, both a constitutively active GPA2 allele and deletion of KRH1/2 lower the cAMP requirement of PKA for growth [2].
• Krh1 directly interacts with PKA by means of the catalytic subunits, and Krh1/2 stimulate the association between the catalytic and regulatory subunits in vivo [2].
• Strains containing deletions of KRH1 and its homolog KRH2 were hyper-invasive and displayed a high level of expression of FLO11, a gene involved in pseudohyphal and invasive growth [3].
• Given that these three enzymes control the synthesis and degradation of cAMP, these results indicate that the effect of Gpb1p and Gpb2p on PKA substrate phosphorylation does not occur by regulating the intracellular cAMP concentration [4].

Biological context of GPB2

• Krh1p and Krh2p act downstream of the Gpa2p G(alpha) subunit to negatively regulate haploid invasive growth [3].

Physical interactions of GPB2

• A two-hybrid screen using a constitutively active allele of GPA2 identified the KRH1 gene as encoding a potential binding partner of Gpa2p [3].

References