When the Ca2+ levels drop:

Myosin LC is dephosphorylated by MLC phosphatase, causing muscle relaxation.

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#Id: 3803

#Unit 5. Developmental Biology

When the ratio of PSF relative to that of bacteria exceeds a certain threshold, cells stop proliferating and initiate the expression of genes that are required for their aggregation.

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#Id: 3804

#Unit 5. Developmental Biology

Early on during aggregation, gene expression requires the activity of cAMP-dependent protein kinase.

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#Id: 3805

#Unit 5. Developmental Biology

High PSF to food ratio is upregulate the translation of the PKA catalytic subunit PKA-C.

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#Id: 3806

#Unit 5. Developmental Biology

A second glycoprotein secreted during starvation is CMF (conditioned medium factor)

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#Id: 3807

#Unit 5. Developmental Biology

CMF stimulates gene expression in parallel with PSF, and both signals potentiate cAMP signalling by inducing genes involved in cAMP synthesis and detection

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#Id: 3808

#Unit 5. Developmental Biology

Newly activated genes are:

Adenylate cyclase A (ACA)

PKA

Extracellular cAMP phosphodiesterase PdsA

An intracellular cAMP phosphodiesterase RegA