Surface protein not present in Red blood cell membrane is:

Ref: Robbins Pathologic Basis of Disease, 8th edition, Pg: & Ganong Circulation . introduction. & Labeit S, Ottenheijm CA, Granzier H. Nebulin, a major player in muscle health and disease, EASEB J. 2011;25:822-829.Explanation:"Thus, nebulin is emerging as a thin-filament length stabilizer that, in skeletal muscle, ensures the assembly of much longer act in filaments than are found in other cell types where nebulin is absent (such as red blood cells, where act in filaments are only 20-50 nm"(Labeitetal).Nebulin is an actin-binding protein which is localized to the thin filament of the sarcomeres in skeletal muscle.It is a very large protein (600-900 kDat and binds as many as 200 actin monomers.Because its length is proportional to thin filament length, it is believed that nebulin acts as a thin filament "ruler" and regulates thin filament length during sarcomere assembly.Actin, spectrin, ankyrin and glycophorin C are integral part of RBC membraneMutation of genes encoding these proteins give rise to structural RBC disorders like Hereditary spherocytosis (HS).Hereditary spherocytosis (HS)In HS is caused by diverse mutations that lead to an insufficiency of membrane skeletal components. As a result of these alterations, the life span of the affected red cells is decreased on average to 10 to 20 days from the normal 120 days.The pathogenic mutations most commonly affect ankyrin. hand 3, spectrin, or band 4.2.Most mutations cause shifts in reading frame or introduce premature stop codons, such that the mutated allele fails to produce any protein.The defective synthesis of the affected protein reduces the assembly of the skeleton as a whole and results in a decrease in the density of the membrane skeleton components.Young HS red cells are normal in shape, but the deficiency of membrane skeleton reduces the stability of the lipid bilayer, leading to the loss of membrane fragments as red cells age in the circulation.The loss of membrane relative to cyt oplasm "forces" the cells to assume the smallest possible diameter for a given volume, namely, a sphere.