Research Paper Volume 8, Issue 2 pp 366—381

Permanent farnesylation of lamin A mutants linked to progeria impairs its phosphorylation at serine 22 during interphase

Figure 4. Flavopiridol sensitive kinases control serine 22 phosphorylation of non-farnesylated progerin and mature lamin A. (A) Immunofluorescence with anti-lamin A/C (LamA/C, green) and antibodies against indicated kinases (red) in U-2 OS cells expressing R50P mutant of non-farnesylated progerin (R50PprogerinCS). (B) Phosphoserine 22 lamin A immunoblots in U-2 OS cells expressing non-farnesylated progerin (ProgerinCS) treated with 100 nM flavopiridol or vehicle for 2 days. (C) Lamin A and phosphoserine 22 lamin A immunoblots and phosphoserine 22 lamin A/lamin A (p-S22 LamA) quantified immunoblots and expression ratio estimation of phosphoserine 22 lamin A/lamin A (pS22/LamA) in U-2 OS cells expressing mature lamin A treated with 1 μM PD0332991 (PD) or 100 nM flavopiridol (Flav) or vehicle for 2 days. (D) Lamin A and CDK6 immunoblots in U-2 OS cells expressing shCDK6s or a control shRNA (V). (E) Immunofluorescence for lamin A/C and CDK6 in cells as in (D). Scale bar: 10 μm.