The Src Kinase Can Be Regulated by at Least Two

question 20

Short Answer

The Src kinase can be regulated by at least two mechanisms. Kinases of the CSK family inactivate Src by phosphorylating a C-terminal tyrosine residue. On the other hand, binding of activating ligands (including some activated receptor tyrosine kinases, or RTKs) results in autophosphorylation at a tyrosine residue near the active site, stimulating Src activity. Full activation of Src therefore requires both dephosphorylation at the inhibitory tyrosine and binding to an RTK. Which of the following logic gates (A to E) correctly models the activation of Src kinase (output) as a function of the activity of the upstream regulators (inputs)?

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Definitions:

Depreciation

The accounting process of allocating the cost of tangible assets over their useful lives, reflecting wear and tear, or obsolescence.

Capital Gain/Loss

The profit or loss made from selling an asset for more or less than its purchase price.

Depreciates

The process by which an asset loses value over time, often due to wear and tear, age, or obsolescence, impacting its useful life.

Straight Line

A method of calculating depreciation of an asset which assumes equal annual depreciation over the asset's useful life.