An intact helical domain is required for Gα14 to stimulate phospholipase Cβ

BMC Structural Biology

Table 1 Functional characterizations of the chimeras and their correlation with intact PLCβ or Gα₁₄ helical domains

	PLCβ stimulation	Adenylyl cyclase inhibition	PLCβ interaction	TPR1 interaction	Intact PLCβ domain	Intact Gα₁₄ helical domain
Gα₁₄	Yes	No	Yes	Yes	Yes	Yes
203z14	No	No	No	Yes	Yes	No
14z151	Yes	No	Yes	Yes	No	Yes
182z14	No	No	No	Yes	Yes	No
14z173	Yes	No	Yes	Yes	No	Yes
14β2β3	No	Yes	No	No	No	No
zβ2β3	Yes	No	Yes	Yes	Yes	Yes
14z224	No	Yes	No	Yes	No	No
131z14	No	No	No	Yes	Yes	No
14αDEF	No	Yes	No	Yes	No	No
zαDEF	No	No	No	No	Yes	No
14α2β4α3	No	Yes	No	Yes	No	No
zα2β4α3	Yes	No	Yes	Yes	No	Yes
14αN	No	Yes	No	No	No	No
zαN	Yes	No	Yes	Yes	Yes	Yes
Gα_z	No	Yes	No	No	No	No

Results of Gα proteins and chimeras in functional studies and co-immunoprecipitation assays are summarized. PLCβ stimulation was determined by measuring IP₃ production by constitutively active (QL) chimeras as compared to their corresponding wild type activity (Figs. 2c, 3c, 4c, and 5c). The ability of QL-chimeras to inhibit adenylyl cyclase was determined in FSK-induced cAMP accumulation assays (Fig. 6a). Co-immunoprecipitation assays were performed using anti-PLCβ2 and anti-FLAG for the detection of PLCβ (Figs. 2b, 3b, 4b, and 5c) and TPR1 (Fig. 6b), respectively. Constructs containing an intact PLCβ binding domain (α2-β4-α3-β5 region) or an intact helical domain (αA-αF region) of Gα₁₄ are also shown

ISSN: 1472-6807