Amino Acid Phosphorylation

Staurosporine a protein kinase inhibitor would:

Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are key drugs for EGFR mutation-positive non-small cell lung cancers (NSCLCs), most patients become resistant to the drugs within 1 year. Which of the following mutations could account for growing resistance in NSCLCs to EGFR-TKIs? (Read the hint to learn about the notation in the answer choices.)

Adapted From: Tomoaki Sonoda, Shingo Nishikawa, Rie Sakakibara, Masafumi Saiki, Ryo Ariyasu, Junji Koyama, Satoru Kitazono, Noriko Yanagitani, Atsushi Horiike, Fumiyoshi Ohyanagi, Hironori Ninomiya, Yuichi Ishikawa, Makoto Nishio, EGFR T790M mutation after chemotherapy for small cell lung cancer transformation of EGFR-positive non-small cell lung cancer, Respiratory Medicine Case Reports, Volume 24, 2018

Oct4 is a key component of the molecular circuitry that regulates embryonic stem cell proliferation and differentiation. It is essential for the maintenance of undifferentiated, pluripotent cell populations, and accomplishes these tasks by binding DNA in multiple heterodimer and homodimer configurations. Very little is known about how the formation of these complexes is regulated, or the mechanisms through which Oct4 proteins respond to complex extracellular stimuli which regulate pluripotency. Here, we provide evidence for a phosphorylation-based mechanism that regulates specific Oct4 homodimer conformations. Point mutations of a putative phosphorylation site can eliminate transcriptional activity of a specific homodimer assembly, with little effect on other configurations.

Which of the following point mutations is likely to interfere with the transcriptional activity of Oct4?

Upon phosphorylation, serine would be most similar to which of the following amino acids?

Elimination of phosphatase activity, which is an enzyme class that removes phosphate groups from molecules, would leave threonine and tyrosine residues most similar to what class of amino acids?

One of the three amino acids that can be phosphorylated is classified as what type of amino acid?

Which of the following amino acids CAN’T be phosphorylated?