Methods for predicting kinase inhibitor resistance

A method of measuring the presence or absence of drug resistance of a mutant kinase, comprising:

• (a) expressing in each of a plurality of eukaryotic cells:
• (i) a first fusion protein comprising an ER targeting sequence, a mutant kinase, and an ER retention sequence, wherein the mutant kinase comprises at least one point mutation relative to wild-type;
• and
• (ii) a vector encoding a second fusion protein comprising:
• an endoplasmic reticulum (ER) targeting sequence, a surface expression sequence, a first peptide sequence, and an endoplasmic reticulum (ER) retention sequence;
• wherein the eukaryotic cells are exposed to a kinase inhibitor during said expression wherein the kinase inhibitor is a tyrosine kinase inhibitor;
• (b) separating or purifying said eukaryotic cells based on the presence or absence of phosphorylation of at least one amino acid of the first peptide on the surface of the eukaryotic cells;
• wherein the presence or absence of phosphorylation is detected with an antibody, wherein the presence of phosphorylation indicates enzymatic activity of the mutant kinase, wherein enzymatic activity in the presence of the kinase inhibitor indicates resistance to the kinase inhibitor;
• and
• (c) sequencing the mutant kinase;
• wherein the mutant kinase is a tyrosine kinase.