Overexpression of protein 'X' in the muscle cells of Caenorhabditis elegans leads to an abnormal shortening of body length. When a mutant allele of 'X' that cannot bind ATP is overexpressed, the phenotype is not observed. Simultaneous knockdown of protein 'Y' in the skin cells prevents the abnormal body shortening even when 'X' is overexpressed. Proteins 'X' and 'Y' physically interact in the muscle cell lysates.
Which of the following inferences would be the most accurate?
1
Protein 'X' directly regulates cell shape in a cell-autonomous manner, while 'Y' is involved in muscle ATP metabolism.
2
'X' acts as a signaling molecule in muscle cells, and 'Y' is a receptor on the skin cells.
3
'X' is a secreted ligand from the muscle cells, and 'Y' is a receptor in skin cells involved in controlling body length.
4
'X' is an enzyme in muscle cells, and 'Y' is a downstream effector in the skin cells.