When blood glucose rises above 5 mM, hexokinase IV activity increases, but hexokinase I is already operating near Vmax and cannot respond to an increase in glucose concentration. 

TLS Online TPP Program

#Id: 9468

#XL - T Zoology

Erythropoietin receptor & the receptors for GH, prolactin, G-CSF, activates STAT5 but not STATs 1, 2, 3, or 4. 

TLS Online TPP Program

#Id: 9469

#XL - T Zoology

IL-2 receptor complex activates

STATs 1, 3, and 5 but not STATs 2 or 4

TLS Online TPP Program

#Id: 9470

#XL - T Zoology

Phosphorylated STAT dissociates spontaneously from the receptor, and two phosphorylated STAT proteins form a homodimer.

TLS Online TPP Program

#Id: 9471

#XL - T Zoology

STAT5 becomes activated in erythroid progenitor cells and induces expression of the protein Bcl-xL.

TLS Online TPP Program

#Id: 9472

#XL - T Zoology

Two mechanisms for terminating cytokine signaling:

1. Short-term regulation: SHP1

2. Long-term regulation: SOCS proteins

TLS Online TPP Program

#Id: 9473

#XL - T Zoology

SHP1 a phosphotyrosine phosphatase, contains:

SH2 domain  & Phosphatase domain