Regulator of G Protein Signaling Proteins Control Growth, Development and Cellulase Production in .

Heterotrimeric (αβγ) G protein signaling pathways are critical environmental sensing systems found in eukaryotic cells. Exchange of GDP for GTP on the Gα subunit leads to its activation. In contrast, GTP hydrolysis on the Gα is accelerated by Regulator of G protein Signaling (RGS) proteins, resulting in a return to the GDP-bound, inactive state.

Heterotrimeric G-Protein Signaling Is Required for Cellulose Degradation in Neurospora crassa.

The filamentous fungus decomposes lignocellulosic biomass to generate soluble sugars as carbon sources. In this study, we investigated a role for heterotrimeric G-protein signaling in cellulose degradation. Loss of the Gα subunit genes and , the Gβ subunit genes and , the Gγ gene , or the gene for downstream effector adenylyl cyclase () resulted in loss of detectable cellulase activity.

Genetic relationships between the RACK1 homolog cpc-2 and heterotrimeric G protein subunit genes in Neurospora crassa.

Receptor for Activated C Kinase-1 (RACK1) is a multifunctional eukaryotic scaffolding protein with a seven WD repeat structure. Among their many cellular roles, RACK1 homologs have been shown to serve as alternative Gβ subunits during heterotrimeric G protein signaling in many systems. We investigated genetic interactions between the RACK1 homolog cpc-2, the previously characterized Gβ subunit gnb-1 and other G protein signaling components in the multicellular filamentous fungus Neurospora crassa.