Figure 3.

A, Leucine-degradation pathway. The absence of MCC leads to the accumulation of the upstream compounds isovaleryl-CoA and methylcrotonyl-CoA, which lead to 3-hydroxyisovaleric (3-HIVA) and 3-methylcrotonylglycine (3-MC-Gly), which are biochemical landmarks of the isolated, biotin-insensitive MCC deficiency. B, Multitissue northern blot hybridization, showing coordinated, high-level expression of MCCA and MCCB in liver, kidney, heart, and skeletal muscle. β-Actin was used as a loading control. MCCA and MCCB probes were ESTs “AA605162” and “AI949422,” respectively. B = brain; H = heart; SM = skeletal muscle; C = colon; T = thymus; S = spleen; K = kidney; Li = liver; Si = small intestine; P = placenta; Lu = lung; PBL = peripheral blood lymphocytes. The human multiple-tissue northern filter was purchased from Clontech.